WO2004007385A1

WO2004007385A1 - Glass, optical waveguide manufacturing method, and optical waveguide

Info

Publication number: WO2004007385A1
Application number: PCT/JP2003/009039
Authority: WO
Inventors: Tatsuo Nagashima; Hiroshi Wakatsuki; Naoki Sugimoto; Yuki Kondo; Shotaro Takenobu; Setsuro Ito
Original assignee: Asahi Glass Company, Limited
Priority date: 2002-07-16
Filing date: 2003-07-16
Publication date: 2004-01-22
Also published as: JP2004102210A; AU2003280978A1

Abstract

A glass substantially comprising 6-55% of Bi2O3, 10-70% of SiO2, 3-40% of P2O5, 5-30% of Li2O+Na2O+K2O+Rb2O+Fr2O, 0-40% of Al2O3, 0-30% of MgO+CaO+SrO+BaO+ZnO, 0-20% of B2O3, 0-20% of GeO2, 0-20% of TiO2+ZrO2+SnO2+Y2O, and 0-10% of CeO2. An optical waveguide manufacturing method characterized in that the glass is subjected to two-stage thermal ion exchange.

Description

Glass, optical waveguide manufacturing method and optical waveguide

The present invention relates to a bismuth oxide-based glass suitable for ion exchange, an optical waveguide manufacturing method, and an optical waveguide. Background art

For the purpose of application to optical amplifiers used in wavelength division multiplexing optical communication systems, Er-doped bismuth oxide-based optically amplifying glass fibers that do not easily cause concentration quenching and can achieve desired optical amplification with a short length have been proposed. (See, for example, pages 2 to 4 of JP-A-2001-106261).

In addition, bismuth oxide-based glass fibers that have a large third-order nonlinear optical effect and are suitable for a third-order nonlinear optical element such as an ultrahigh-speed optical switch or a wavelength conversion element have been proposed (see, for example, Japanese Patent Application Laid-Open No. 2001-212136). No. 40, pages 2-5).

In these examples, a glass fiber having a core Z-clad structure is used as an optical waveguide, but various optical waveguides in which an optical waveguide is embedded in glass by ion exchange have been proposed (for example, see Japanese Patent Application Laid-Open No. 2002-202). (See pages 2 to 4 of Japanese Patent Publication No. 288861).

Bismuth oxide glass used for such a glass fiber is required not to be devitrified when the fiber is applied. On the other hand, such a restriction may reduce the optical amplification function or the third-order nonlinear optical effect of bismuth oxide glass.

On the other hand, the optical waveguide proposed in Japanese Patent Application Laid-Open No. 2000-228681 is manufactured without fiber processing, but has a low refractive index of 1.50 or less. Of rate. Therefore, the third-order nonlinear optical effect is small, and it is difficult to apply it to optical amplification applications.

The present invention realizes light by performing ion exchange processing without fiber processing. An object of the present invention is to provide a bismuth oxide-based glass applicable to an optical waveguide such as an amplifier, such an optical waveguide, and a method for manufacturing the same. Disclosure of the invention

The present invention, in mol% based on the following _{_{oxides, B i 2 0 3 6~55%}} , S i O 2 10~70%, P 2 O 5 3~40%, L i 2 0 + Na 2 0 _{+ K 2 O + Rb 2 O} + F r 2 O 5~30%, A l 2 O 3 0~ 40%, M g O + C a O + S r O + B aO + Z nO 0~30%, B ₂ 0 ₃ 0 to 20%, Ge ₂ 0 to 20 T i 0 ₂ + Zr 0 ₂ + Sn 0 ₂ + Y ₂ 0 ₃ 0 to 20%, CeO ₂ 0 to 10%, force Essential glass I will provide a.

Further, the present invention provides a method for producing an optical waveguide, wherein the glass is subjected to two-stage thermal ion exchange, wherein the glass is the glass of the present invention. An optical waveguide in which the Ag-containing optical waveguide is embedded by performing two-stage thermal ion exchange on glass having a refractive index of 1.6 or more, and where the Ag-containing optical waveguide has the highest Ag content An optical waveguide characterized in that the shortest distance between the glass and the glass surface is 1 m or more. BEST MODE FOR CARRYING OUT THE INVENTION

The glass of the present invention is usually made into an optical waveguide by performing a two-stage thermal ion exchange known in JP-A-6-194533 and the like, and the optical waveguide is connected to a silica glass fiber or the like. The method for manufacturing the optical waveguide is the method for manufacturing an optical waveguide of the present invention (hereinafter, referred to as the method of the present invention).

The two-step thermal ion exchange method is a method in which a glass (ion-exchanged glass) on which an ion exchange mask has been formed other than a part to constitute a waveguide is immersed in an ion exchange melt A and the mask is not masked. That is, primary ion exchange is performed to form a high-refractive-index ion-exchange layer (hereinafter, referred to as a high-refractive-index layer) in a portion where a waveguide is to be formed. Another ion replacement for embedding The glass is immersed in the melt B, and secondary ion exchange is performed by applying an electric field.

If the glass of the present invention performs a two-stage heat Ion exchange to the glass containing N a, for example, ion exchange melt A AgN_〇 ₃ melt, the melt B ion exchange is NaN 〇 ₃ melt .

If ion exchange melt B is, for example, N a NO ₃ melt, the melt A ion exchange may be is not for example L i N0 ₃ melt limited to AgNO ₃ melt, high refractive Oriritsu the or when you want to adjust the refractive index of the layer may be a mixed melt of L i N0 _{_3,} NaN0 ₃ and KN0 ₃ 1 or more selected from the group consisting of Al force Li metal nitrate and a Gno _s.

Further, in order to prevent roughening of the glass surface after ion exchange as used those containing A g NO ₃ as an ion exchange melt A, AgNO ₃ than have high melting points even L iN0 _{_3,} NaN0 ₃ , good Masui be those containing together KN0 ₃ or the like.

The ion exchange melt A and the ion exchange melt B are not limited to these. The temperature of the ion exchange melt in the primary ion exchange and the secondary ion exchange is preferably 25 Ot or more. If this temperature is lower than 250 ° C, the time required for ion exchange may be prolonged. The temperature is more preferably 300 or more, particularly preferably 320 or more. Further, it is preferable that the temperature is below glass transition temperature T _e of the ion-exchange glass. The glass surface of the ion after replacing said temperature is higher than T _e tends rough. The temperature is more preferably (T _e —50 ° C.) or less, particularly preferably (T _e —100) or less.

The ion exchange time in the primary ion exchange is preferably from 10 minutes to 48 hours. If the ion exchange time is less than 10 minutes, it becomes difficult to obtain a high refractive index layer having a desired thickness. The ion exchange time is more preferably at least 1 hour, particularly preferably at least 2 hours. If the ion exchange time is longer than 48 hours, the glass surface after ion exchange tends to be rough. The ion exchange time is more preferably 16 hours or less, particularly preferably 8 hours or less. In the primary ion exchange, an electric field may be applied in order to obtain a high-refractive-index layer having a desired thickness in a shorter time. The electric energy at this time is, for example, 0.01 to L00W * h. The ion exchange time in the secondary ion exchange is preferably 10 minutes or more and 12 hours or less. If the ion exchange time is less than 10 minutes, it becomes difficult to move the high refractive index layer into a glass having a desired depth to form an optical waveguide. The ion exchange time is more preferably at least 20 minutes, particularly preferably at least 30 minutes. On the other hand, if the ion exchange time exceeds 12 hours, the glass surface after ion exchange tends to be rough, or the symmetry of the optical waveguide portion is reduced, making single mode propagation difficult. The ion exchange time is more preferably 4 hours or less, particularly preferably 2 hours or less.

The electric energy when applying an electric field in the secondary ion exchange is preferably 0.01 to 100 W-h. If the electric power is less than 0.01 W * h, it becomes difficult to move the high refractive index layer into the glass having a desired depth to form an optical waveguide. The electric energy is more preferably 0.1W * h or more. On the other hand, if the power exceeds 100 W · h, the symmetry of the optical waveguide is reduced, and it becomes difficult to propagate the sinal mode. The electric energy is more preferably 10 W · h or less.

Next, the glass of the present invention will be described.

The glass of the present invention is suitable for producing an optical waveguide by performing two-stage thermal ion exchange.

When the glass of the present invention is used for producing an optical amplification waveguide, the glass of the present invention may contain at least one rare earth element selected from the group consisting of Er, Tm, Pr and Dy. preferable.

Refractive index _{5 5} of the glass of the present invention, the wavelength 1550 nm for light. Is preferably 1.6 or more. _{If the value of} 55Q is less than 1.6, the optical amplification factor or the third-order nonlinear optical effect may be reduced. _{5 5} . Is more preferably 1.65 or more, further preferably 1.7 or more, particularly preferably 1.8 or more, and most preferably 1.9 or more. Also, 1 ^ _55Q is typically less than 2.5.

The _TG of the glass of the present invention is preferably 360 ° C. or higher. T is 360 ° C If it is less than 1, the temperature of the melt cannot be increased when performing ion exchange, and the ion exchange efficiency may be reduced. May be thermally damaged. _Te is preferably at least 400 ° C, more preferably at least 450 ° C, particularly preferably at least 480 ° C.

Devitrification temperature T _D of the glass of the present invention is preferably less than 1150 ° C or less, or 1150 ° C. T _D is likely to crystallize when the glass is melted at 1150 ° C or more than 1 0.99 ° C or higher. T _D is more preferably 1125 ° C or less, or 1125 ° C less than, particularly preferably 1100 ° C or less, or less than 1100 ° C.

T _D in the present invention is as follows. That is, about 5 pieces of glass placed on a 40 mm × 40 mm × 1 mm platinum dish are put into a furnace at a predetermined temperature, and after holding for 2 hours, taken out of the furnace and cooled. The cooled glass sample is observed using a polarizing microscope, and と is used for Mitutoyo Mesureng fin scone MF200 manufactured by Mitutoyo Co., Ltd. to check for crystal precipitation. Wherein the predetermined temperature when crystallization is observed below T _D, the plant constant temperature in the case where crystallization is not observed is higher than T _D.

Next, the composition of the glass of the present invention will be described by simply indicating mol% as%.

B i ₂ 0 ₃ is essential a component to increase the refractive index. The content of B i ₂ 0 ₃ is the refractive index becomes small at less than 6%. This content is preferably at least 10%, more preferably at least 12.5%, particularly preferably at least 15%. If the content is more than 55%, T _D becomes high, _Te becomes high, or the difference in the refractive index between the ion-exchanged portion, that is, the ion-exchanged layer and the non-ion-exchanged portion becomes small. . The content is preferably 40% or less, more preferably 30% or less.

S i 0 ₂ is essential is a network follower one Ma. The content of S i 0 ₂ becomes difficult to vitrification is less than 10%, the refractive index becomes small at 70%. This content is preferably at least 20%, more preferably at most 50%, more preferably at most 35%.

P ₂ 〇 ₅ ion exchange, alkali metal I in the glass, especially using the Ag-containing melt It is a component that increases the efficiency of the process of exchanging ON for Ag ions and is essential. In this fluorine organic content is less than 3%, for example, the ion-exchange ToruTomo A two stage thermal ion exchange silver colloid is generated in the high refractive index layer when the AgNO ₃ melt, the melt B ion-exchange It becomes difficult for the high refractive index layer to move into the glass by immersion and application of an electric field. P ₂ 0 content of ₅ preferably 9% or more, more preferably over 11% or more. If the content is more than 40%, the chemical durability becomes poor or the glass becomes difficult. P ₂ 0 content of ₅ or less preferably 30%, more preferably 20% or less.

It is preferable that the total content of S I_〇 ₂ and P ₂ 0 ₅ is 30% or more.

Li ₂₀ , Na ₂₀ , K ₂₀ , Rb ₂ O, and Fr ₂ O are components for ion exchange and must contain at least one of them. If the total content of these alkali metal oxides is less than 5%, the refractive index of the ion exchange layer will be small. The sum of these contents is preferably at least 7.5%. In total 3 0% of these contents, vitrification tends to be difficult, T _e is low, or the weather resistance is lowered. It is more preferably at most 25%, particularly preferably at most 20%.

It preferably contains at least one of Li ₂ O and Na ₂ O, and more preferably contains Na ₂ O.

When containing Na ₂ O, the content thereof is 5 to 20% or preferably, yo Ri is preferably 7.5% or more. In this case, an alkali metal oxide other than Na ₂ O may or may not be contained.

In the case of making the glass of the present invention more difficult to devitrify, etc., it is preferable that the glass does not contain { ₂ }.

Although A 1 ₂ 0 ₃ is not essential, it may have free up to 40% in order to increase the ion exchange efficiency. If it exceeds 40%, it tends to crystallize when the glass is melted, and the transmittance of the glass may decrease. This content is preferably at most 30%, more preferably at most 20%. Its content when they contain A l ₂ 0 ₃ is preferably at least 1%, more preferably 5% or more, particularly preferably 8% or more.

MgO, CaO, Sr〇, BaO and ZnO are all optional, In order to stabilize the glass, it may be contained up to a total of 30%. If the total of these contents exceeds 30%, crystallization may be likely to occur when the glass is melted. The total of these contents is preferably 20% or less, more preferably 10% or less.

Among these five components, it is preferable to contain 1 to 10% of BaO.

Although ₂ 0 ₃ is not essential B, and for ease of glass formation by low T _D, or but it may also contain up to 20% in order to increase the wavelength width of the optical amplification gain. When the content of B ₂ 0 ₃ is more than 20%, it may become difficult to fluorescence lifetime Maruchifuonon relaxation is increased is used becomes light amplifying short. This content is preferably less than 7.5%.

Ge0 ₂ is not essential, but may be incorporated up to 20% has higher to that effect the refractive index with ease glass formation. If the content exceeds 20%, the glass may be easily crystallized. This content is preferably at most 10%, more preferably at most 5%. When containing ge0 _2, its content is preferably 1% or more 0.1, more preferably 1% or more.

T i0 _2, Z R_〇 _2, but Sn_〇 ₂ and Y ₂ 〇 ₃ is not essential, but 20% in order to suppress devitrification of glass during fabrication, or in total in order to adjust the refractive index It may be contained in the range up to. If the total of these contents exceeds 20%, the glass may be easily crystallized. The total of these contents is preferably 10% or less, more preferably 5% or less.

Although C eO _a is not essential, in order were suppresses the B i ₂ 0 ₃ in the glass composition reduces the transparency of the glass is reduced in the glass melting precipitated as metal bismuth, containing up to 10% May be. Ce0 the content of ₂ 10%, the vitrification becomes difficult, or there is a risk that a yellow or orange coloration is strong for connexion glass transmittance is reduced. This content is preferably at most 1%, more preferably at most 0.5%, particularly preferably at most 0.3%.

When containing ce0 _2, preferably it has a content is 0.01% or more, more preferably 0.05% or more, particularly preferably 1% or more 0.1. Incidentally, if it is desired to avoid a reduction in the transmittance of the glass, the content of CeO ₂ is preferably set to 0.1 less than 15%, the glass of the preferred present invention may not contain CeO ₂ substantially it is essentially It consists of the above components, but may contain other components as long as the object of the present invention is not impaired. The total content of the other components is preferably 30% or less, more preferably 20% or less, and particularly preferably 15% or less. For example, when the glass of the present invention is used for manufacturing an optical amplification waveguide, the following components may be mentioned as preferable ranges of the other components and the following oxide standards. It should be noted that the following components may be contained in a range that does not impair the object of the present invention even when the glass of the present invention is not used for manufacturing an optical amplification waveguide.

Pra 0 ₃ + Dy 2 0 ₃ + E r ₂ 0 ₃ + Tm ₂ 0 ₃ : 0.1 to 5%

P r _₂ 0 _3, Dy ₂ 〇 _{_3,} E r ₂ 0 ₃ and Tm ₂ 0 ₃ is a component having an optical amplification function, it is preferable to contain one or more either. If the total content of these four components exceeds 5%, there is a possibility that a desired optical amplification factor cannot be obtained due to concentration quenching, or glass is crystallized. The total of these contents is more preferably from 0.2 to

2%.

C Pando (wavelength: 1,530 to 1,560 nm) or L band (wavelength: 1570 to 1600 nm) for the case of optical amplification in E r (E r ₂ 〇 _3), S + bands (wavelength: 1450~1490nm) Or S band (wavelength: 1490-15

The Tm (Tm ₂ 0 ₃₎ When performing optical amplification in 30 nm), the case of performing optical amplification in the 1300 nm band _{_{P r (P r 2 0 3}} ) or Dy a (Dy ₂ 0 _3), containing respectively Is preferred.

_{_{_{Ga 2 0 3 + Te0 2 +}}} L a 2 O s + WO s: 0. 1~30%

These 4 content of the component may cause personal to connexion glass crystallization of high T _D is 30 percent. The total of these contents is more preferably from 1 to 20%, particularly preferably from 2 to 20%.

Ga ₂ 0 ₃ is the optical amplification factor large especially if it is less 25% B i ₂ 0 ₃ content This has the effect of increasing the gain or increasing the wavelength width over which gain can be obtained. Its content when containing Ga ₂ 0 ₃ is 2 is preferably 25%. If the content is more than 25%, crystals may precipitate during glass production, and the transmittance of the glass may be reduced. The content of Ga ₂ 0 ₃ is more preferably 5-20%, particularly preferably 5-15%.

Te0 ₂ has the effect of increasing the optical amplification factor. Its content when they contain te0 ₂ is preferably 1 to 20%. If the content is more than 20%, crystals may precipitate during glass production, and the transmittance of glass may decrease. The content of Ga ₂ 0 ₃ is more preferably from 2 to 5%.

L a ₂ 0 _3, especially has the effect of preventing concentration quenching raise its dispersibility in the case of containing E r ₂ 0 _3. Its content when they contain L a ₂ 0 ₃ is preferably 1-20% der Rukoto 0.5, may decrease the transmittance of the glass to precipitate crystals during glass making is 20 percent.

Preferably L a ₂ 〇 ₃ content in the case of containing _{_{E r 2 0 3 0. 1~1%}} 0. 1% or more and less than 1%, more preferably less than 1% 5% or more 0.5.

When containing E r ₂ 0 ₃ exceeds 1% 5% range, L a ₂ 0 ₃ content is preferably:! -20%, more preferably 2-5%.

wo ₃ has the effect of increasing the wavelength width over which gain can be obtained. When wo ₃ is contained, its content is preferably 1 to 10%, and if it exceeds 10%, the optical amplification factor may be reduced. This content is more preferably 2-5%.

The Yb ₂ 0 ₃ may have free for such increase the optical amplification factor in case of containing E r ₂ 0 _3. Its content when containing Yb ₂ 0 ₃ is preferably 1-5% 0.1.

The other components in the glass of the present invention are not limited to the components described above, but when CdO is contained, it is preferable that Zn0 + CdO is 5% or less.

Next, the optical waveguide of the present invention will be described.

The optical waveguide of the present invention _{5 5.} It is manufactured by performing two-stage thermionic exchange on glass with a ≧ 1.6. Tertiary nonlinear optical effect since ₅ 5 _Q of the glass is at 1.6 or greater. Further, in order to use in an optical amplifier for example, the glass is E r, Tm, one or more rare earth elements selected from the group consisting of P r, and Dy _{_{contained, P r 2 0 3 + Dy}} 2 0 3 + E r If ₂ 0 _₃ + Tm 2 0 ₃ is 1 to 5 mol% 0., it becomes one whose light amplifying properties are excellent. _{55 Q} is preferably 1.7 or more, more preferably 1.8 or more, and particularly preferably 1.9 or more.

Furthermore, the glass preferably contains B i ₂ 0 _3, S I_〇 _2, P ₂ 0 ₅ and alkali metal oxides.

If not containing B i ₂ 0 ₃ _{5 5.} It becomes difficult to make it 1.6 or more.

More preferably contains B i ₂ 0 ₃ 1 0 mol% or more.

Vitrification tends to be difficult and does not contain a S i 0 _2. The S i 0 ₂ and more preferably has containing 20 mol% or more.

P ₂ 0 ₅ containing no the efficiency of the two-stage heat ion exchange process to form a Ag-containing light waveguide may be lowered. And more preferably contains P ₂ 0 ₅ to 9 mol% or more.

If the metal oxide is not contained, it is difficult to perform two-stage thermal ion exchange. More preferably, Na ₂ O is contained in an amount of 7.5 mol% or more.

The glass is preferably the glass of the present invention.

The Ag-containing optical waveguide in the optical waveguide of the present invention is embedded in the glass by performing two-stage thermal ion exchange, and the two-stage thermal ion exchange is performed by the method of the present invention described above. This is the same as the two-step thermal ion exchange except that the ion exchange melt (ion exchange melt A) used for the primary ion exchange is limited to the Ag-containing melt.

The ion exchange melt A, AgNO ₃ melt, L i N0 _{_3,} NaN0 ₃ Oyo melt mixture of one or more alkali metal nitrate and A g NO ₃ selected from the group consisting of beauty KN0 _3, Etc. are exemplified.

The ion exchange melt for use in secondary ion exchange (ion exchange melt B), NaN_〇 ₃ melt, in addition to such L i N_〇 ₃ melt, L i NO _s, NaN_〇 ₃ and A mixture of two or more melt mixing melt like alkali metal nitrate selected from the group consisting of KN0 ₃ is exemplified.

Typically, the ion exchange melt A, respectively B A g NO ₃ melt, is NaN0 ₃ melt.

If the shortest distance d between the portion of the Ag-containing optical waveguide having the highest Ag content and the glass surface (the surface of the optical waveguide of the present invention) is less than 1 xm, it becomes difficult to propagate light in single mode. d is preferably 3 m or more, more preferably 5 m or more. d can be determined by measuring the Ag concentration profile of the glass cross section using an EPMA (Electron Beam Microanalyzer) and measuring the shortest distance between the Ag concentration peak position and the glass surface.

The maximum value CA _{g of} the Ag content of the Ag-containing optical waveguide, that is, the Ag content at the Ag concentration peak position is preferably 0.5% or more in terms of mass percentage. If the Ag content is less than 0.5%, the refractive index difference between the Ag-containing optical waveguide (corresponding to the core) and the surrounding cladding becomes too small. This content is more preferably at least 1%, particularly preferably at least 2%. When used for the optical amplification waveguide, it is preferred for obtaining the desired optical amplification factor is C _{A g} is 1% or more.

Also, C _Ag is preferably 10% or less. If C _Ag exceeds 10%, the refractive index difference becomes too large and it becomes difficult to propagate light in single mode. C _Ag is more preferably 7% or less.

The optical waveguide of the present invention and the optical waveguide manufactured by the method of the present invention are capable of transmitting light in a low-loss wavelength region (approximately 1300 to 1650 nm) of a silica glass fiber in a sinal mode. Preferably, when these optical waveguides are optical amplification waveguides, pump light having a wavelength of 900 to 1490 nm is typically used, and such pump light can also propagate in a sinal mode. Is preferred.

In the production of the optical waveguide of the present invention or the method of the present invention, the waveguide is patterned, and then the two-stage thermal ion exchange is performed.

The patterning of the waveguide is performed, for example, as follows. That is, A resist pattern is engraved on the surface of the glass by a photoresist method, and an ion exchange shielding film (for example, an A1 film) is formed on the resist pattern by a sputtering method. Next, the resist is removed by lift-off using an organic solvent, and an ion-exchange mask in which only the ion-exchange shielding film formed on the portion without the resist remains is manufactured.

The width of the ion exchange mask is preferably 1 to 8 xm. When the width is less than 1 nm, connection with a silica glass fiber or the like becomes difficult. When the width is more than 8 nm, light propagation in single mode becomes difficult. This width is more preferably at least 2 m and at most 62 m.

Examples of the ion exchange shielding film include an A1 film and a Ti film.

The thickness is preferably 0.2 to 2 m. If it is less than 0.2 im, a sufficient shielding effect cannot be obtained. Above 2 m, lift-off becomes difficult.

(Example)

Table B i ₂ 0 ₃ Formulation of raw material so as to have the composition shown in column mol% up Yb ₂ 0 ₃ from to prepare a 15 g formulation material and mixed. The prepared raw material was put in a platinum rupo and melted while being kept at 1200 ° C. for 1 hour in an air atmosphere, and the obtained molten glass was poured into a plate shape and air-cooled as it was. Examples 1 to 8 are Examples and Example 9 is a Comparative Example. For the obtained glass, the glass transition point T _e (unit: .C) was determined by differential thermal analysis to determine the devitrification temperature T _D (unit: .C) at 1150 ° (:, 1125 ° C, 1100 ° C, 1075). The temperature was measured using furnaces at different temperatures of 10 ° C and 1050 ° C. In the case where crystal precipitation was observed at 1125 ° C and no crystal precipitation was observed at 1100 ^, “<1125” precipitation If you have not observed and described in the column of T _D of by sea urchin table say, "in the tool 1050".

For Examples 1-3 and 5-9, separately prepare 200 g of the blended raw material, hold it at 1200 ° C for 2 hours, pour the obtained molten glass into a plate shape, and place it in a furnace with a temperature of _TG. After keeping the temperature for a while, the temperature was gradually cooled to room temperature. The obtained glass was processed into a plate with a thickness of 2 mm and a size of 2 OmmX 20 mm, and both surfaces were mirror-polished to obtain a sample plate. The refractive index n _{6 3 3} and the _{5 5} 0 for light with a wavelength of 633 nm of the sample plate was measured using a Metricon Corporation model 2010 prism force bra.

table 1

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6

B i ₂₀ ₃ 14.83 12.48 14.98 14.83 24.95 27.19

S i 0 ₂ 24.71 27.46 24.96 29.65 24.96 19.77

P ₂ O ₅ 14.83 14.98 14.98 12.36 9.99 12.36

N a ₂ 0 14.83 14.98 14.98 12.36 9.88 9.88

A 1 ₂ 0 ₃ 14.83 14.98 14.98 12.36 9.88 12.36

B aO 4.94 4.99 4.99 7.42 4.94 7.42

C e〇 ₂ 0.15 0.15 0.15 0.15 0.15 0.15

Ga ₂ O _s 9.89 9.98 9.99 9.88 9.88 9.88

E r ₂ 0 ₃ 0.99 0 0 0.99 0.99 0.99

Yb ₂ 0 ₃ 0 0 0 0 0 0

T _D <1150 <1125 <1100 <1125 <1125 <1150

T _G 490 495 490 505 480 455

n 633 1.737 1.699 1.732 ― 1.868 1.887

n 1550 1.705 1.673 1.701-1.834 1.852

Table 2

The sample plates of Examples 1, 7, and 9 were subjected to the following ion exchange treatment to evaluate the ion exchange efficiency.

That is, the molar sample plate ratio of 1: 1 and immersion time shown in Table 3 in AgN_〇 ₃ -L i N0 ₃ melt was measured increase .DELTA..eta ₆ 3 3 by ion exchange treatment n _{6 3 3.} Example 1 is for the case where the melt temperature is 320 ^ (example la) and 370 ° C (example lb), and Example 7 is for the case where the melt temperature is 340 ° C (example 7c). For No. 9, each was measured when the melt temperature was 370 ° C. (Example 9b). Table 3 shows the results.

The progress of higher ion exchange Δη ₆ 3 3 reaches the early saturation is considered to be fast.

.DELTA..eta ₆ 3 3 is the melt temperature is 370 ° C, it is preferred ion exchange time is when 0.0 4 or more 1 hour. Table 3

Further, an optical amplification waveguide was produced using the glass of Example 7 as follows. That is, 300 g of the prepared raw material is prepared, kept at 1200 ° C for 2 hours, the obtained molten glass is poured into a mold having an inner diameter of 80 mm, kept at 470 ° C for 4 hours, and then cooled to room temperature. Cooling was performed. The obtained glass was processed into a wafer having a thickness of 1.5 mm and a diameter of 76.2 mm, and both surfaces were mirror-polished to obtain a wafer-like glass.

Waveguide patterning was performed on this wafer-like glass by a photoresist method using an A1 ion-exchange shielding film having a mask width of 3 zm and a thickness of 0.5 m. The wafer-shaped glass ion exchange mask is formed which is produced by the lift-off, the temperature is 340 ° C, the molar ratio of 1: 1 was immersed for 3 hours in AgNO ₃ -L i N0 ₃ melt mixture (primary ion-exchange) Then, the ion exchange mask was polished and removed.

Then, the temperature is immersed in NaN0 ₃ melt 340 ° C, the amount of power shown in Table 4 between the soaked positive electrode-cathode to the melt (unit: W * h) and so as to the electrical field Secondary ion exchange was applied (Example 7, 7β, 7r)

The Ag concentration profile of the cross section of the wafer-like glass after the secondary ion exchange was measured using EPMA, and the above d (unit: m) and C _Ag (unit: mass percentage) were determined. Table 4 shows the results. Table 4

Example 7] With respect to the optical amplification waveguide fabricated in 3), butt-joined both ends of the optical amplification waveguide with bare single mode fiber, and the wavelength when the waveguide length is 1 cm and 2 cm using a parameter meter. The loss for 1300 nm light was measured. As a result, when the waveguide length was 1 cm and 2 cm, the loss was -3.1 dB and -3.6 dB, respectively. The propagation loss calculated from this result was 0.5 dB / cm.

For the optical amplification waveguide fabricated in Example 7/3, the signal enhancement SE was measured as follows. That is, the light from the excitation light source with a wavelength of 98 O nm (excitation power: 75 mW) and the light from the signal light source with a wavelength of 1520 to: L 620 nm (signal power: O dBm) are combined by a WDM power bra. After the wave, the light was input into the optical amplification waveguide, and the light emitted from the waveguide was detected by an optical spectrum analyzer, and SE (unit: dB) was measured.

Tables 5 and 6 show the results for each signal light wavelength (unit: nm) when the waveguide length is 1 cm and 2 cm. If SE is less than 2 dB, it may be noise. From this result, amplification for light with a wavelength of 1520 to 1570 nm is clearly recognized.

Table 5

Wavelength 1520 1525 1530 1535 1540 1545 1550 1555 1560 1565 1570

S E (1 cm) 2.8 2.9 4.6 5.0 4.2 4.0 2.9 3.0 2.5 3.2 2.9

SE (2 cm) 3.3 5.4 8.6 10.0 7.5 6.4 4.8 3.6 3.5 2.0 2.0 Table 6

Industrial potential

According to the present invention, bismuth oxide-based glass applicable to optical waveguides such as optical amplifiers and tertiary nonlinear optical elements by efficient ion exchange processing without fiber processing, and a method for manufacturing such optical waveguides Is obtained. Further, an optical waveguide suitable for an optical amplifier, a tertiary nonlinear optical element, and the like can be obtained.

Claims

Claims In terms of mol% based on the following oxides,

B i ₂₀ ₃ 6-5 5%,

S i 0 ₂ 10 to 70%,

P ₂ o ₅ 3-40%,

_{_{L i 2 0 + Na 2 0}} + K 2 0 + Rb 2 O + F r 2 0 5~3 0%,

A l ₂ 0 ₃ 0 to 40%,

MgO + CaO + S rO + BaO + ZnO 0-30%,

B ₂ 0 ₃ 0-20%,

G e 0 _{20 to 20} %,

T i 0 ₂ + Z r 0 ₂ + S n0 ₂ + Y ₂ 0 ₃ 0 to 20%,

C e 0 ₂ 0-10%, a glass consisting essentially of

2. S i 0 ₂ + glass according to claim 1 P ₂ 〇 ₅ is 30% or more.

3. E r, Tm, contain one or more rare-earth element selected from the group consisting of P r and _{_{D y, P r 2 0 3}} + Dy 2 0 3 + E r 2 0 3 + Tm 2 〇 _3. The glass according to claim 1, wherein ₃ is 0.1 to 5 mol%.

4. Ga, Te, L contains one or more either in a and _{_{W, Ga 2 0 3 + Te0}} 2 + L a 2 0 3 + W0 3 is L.～ 30 mol% claim 3 The glass described in.

5. contain Yb, glass according to claim 3 or 4 Yb ₂ 0 ₃ is 1 to 5 mol% 0.1.

6. The glass according to any one of claims 1 to 5, having a refractive index for light having a wavelength of 1550 nm of 1.6 or more.

7. A method for producing an optical waveguide, characterized by performing two-stage thermal ion exchange on glass, wherein the glass is the glass according to any one of claims 1 to 6.

8. An optical waveguide in which a Ag-containing optical waveguide is embedded by two-step thermal ion exchange in glass having a refractive index of 1.6 or more for light with a wavelength of 1550 nm. An optical waveguide, wherein the shortest distance between the portion having the largest content and the glass surface is 1 // m or more.

9. The optical waveguide according to claim 8, wherein the maximum value of the Ag content in the Ag-containing optical waveguide is 0.5% or more in terms of mass percentage.

10. The optical waveguide according to claim 7, 8 or 9, wherein the glass contains B i ₂ 0 _3, S I_〇 _2, P ₂ 0 ₅ and alkali metal oxides.

11. The glass in mole% based on the following _{_{oxides, B i 2 O 3 6~ 55}} %, S i 0 2 10~70%, P 2 0 5 3~40%, L i 2 0 + Na 2 _{_{0 + K 2 0 + Rb 2}} O + F r 2 O 5~30%, A 1 2 〇 _{3 0~40%, MgO + Ca O} + S r O + B aO + Z nO 0~30%, B 2 _{_{0 3 0~20%, Ge0 2 0~20}} %, T i 0 2 + Z r 0 2 + S nO a + Y 2 O s 0~20%, C e 0 2

11. The optical waveguide according to claim 10, consisting essentially of 0-10%.

12. The glass E r, Tm, contain one or more rare earth elements selected from the group consisting of P r and D y, P r ₂ 〇 _{_{_{3 + Dy 2 0 3 + E}}} r 2 0 3 + Tm ₂ 0 ₃ is an optical waveguide according to any one of claims 8-11 is 0.1 to 5 mol%.