Abstract
The correlation of light from two sources leads to an interference pattern if they belong to a specific time interval known as the coherence time, denoted as Δτ. The relationship governing this phenomenon is ΔτΔν ≈ 1, where Δν represents the bandwidth of the light. This requirement is not satisfied; hence, interference fringes are not observable in the case of ordinary (thermal) light. In the 1950s, Robert Hanbury Brown and Richard Q. Twiss explored interference phenomena using a narrow bandwidth of thermal light. This investigation led to the discovery of the Hanbury Brown and Twiss effect (or the HBT effect in short), which has since found applications in various fields, particularly stellar observations and quantum optics. This article briefly traces the history of the HBT effect and its applications in various fields, including stellar observations. More importantly, it outlines the basic theoretical framework of the HBT effect and presents the design and results of the correlation in intensity fluctuation of a pseudo-thermal light in a college laboratory setting (Michelson interferometer).
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Suggested Reading
B P Abbott, R Abbott, T Abbott, M Abernathy, F Acernese, K Ackley, et al., Gw151226: observation of gravitational waves from a 22-solar-mass binary black hole coalescence, Phys. Rev. Lett., Vol.116, No.24, p.241103, 2016.
A A Michelson and F G Pease, Measurement of the diameter of Alpha-Orionis by the interferometer, Proc. Natl. Acad. Sci., Vol.7, No.5, pp.143–146, 1921.
R Hanbury Brown, R Jennison and M D Gupta, Apparent angular sizes of discrete radio sources: Observations at Jodrell Bank, Manchester, Nature, Vol.170, No.4338, pp.1061–1063, 1952.
R Hanbury Brown and R Q Twiss, Lxxiv. A new type of interferometer for use in radio astronomy, Lond. Edinb. Dublin Philos. Mag. J. Sci., Vol.45, No.366, pp.663–682, 1954.
R Hanbury Brown and R Q Twiss, Interferometry of the intensity fluctuations in light - I. Basic theory: the correlation between photons in coherent beams of radiation, Proc. R. Soc. London Ser. A. Math. Phys. Sci., Vol.242, No.1230, pp.300–324, 1957.
R Hanbury Brown and R Q Twiss, Correlation between photons in two coherent beams of light, Nature, Vol.177, No.4497, pp.27–29, 1956.
R Hanbury Brown, A test of a new type of stellar interferometer on sirius, Nature, Vol.178, No.4541, pp.1046–1048, 1956.
R Hanbury Brown and R Q Twiss, Interferometry of the intensity fluctuations in light - II. An experimental test of the theory for partially coherent light, Proc. R. Soc. London, Ser. A. Math. Phys. Sci., Vol.243, No.1234, pp.291–319, 1958.
Roy J Glauber, The quantum theory of optical coherence, Phys. Rev., Vol.130, No.6, p.2529, 1963.
R Hanbury Brown, J Davis and L Allen, The angular diameters of 32 stars, Mon. Notices Royal Astron. Soc., Vol.167, No.1, pp.121–136, 1974.
J Davis, W Tango, A Booth, T T Brummelaar, R Minard and S Owens, The Sydney University Stellar Interferometer - I. The instrument, Mon. Notices Royal Astron. Soc., Vol.303, No.4, pp.773–782, 1999.
K N Rai, S Basak and P Saha, Radius measurement in binary stars: Simulations of intensity interferometry, Mon. Notices Royal Astron. Soc., Vol.507, No.2, pp.2813–2824, 2021.
K N Rai, S Sarangi, P Saha and S Basak, Simulations of astrometric planet detection in Alpha Centauri by intensity interferometry, Mon. Notices Royal Astron. Soc., Vol.516, No.2, pp.2864–2875, 2022.
Prasenjit Saha, The theory of intensity interferometry revisited, arXiv preprint arXiv:2009.07284, 2020.
Rajaram Nityananda, Measuring the sizes of stars: Fringe benefits of interferometry, Resonance: Journal of Science Education, Vol.22, No.7, pp.645–657, 2017.
Padmanabh Shrihari Sarpotdar, Introduction to the techniques of interferometry and Lunar occultation in radio astronomy, Resonance: Journal of Science Education, Vol.23, No.12, pp.1367–1373, 2018.
Gordon Baym, The physics of Hanbury Brown–Twiss intensity interferometry: From stars to nuclear collisions, Acta Phys. Polonica B, Vol.29, No.7, p.1839, 1998.
Acknowledgement
The authors of this article thank Dr. Akhileshwar Mishra and Navya Paul, both from the Indian Institute for Science Education and Research (IISER), Trivandrum for their invaluable assistance in arranging and enabling the instruments necessary for the experiments reported here. One of the authors (Subrata Sarangi) acknowledges, hereby, the hospitality and support he received as a Visiting Associate at the Inter-University Centre for Astronomy and Astrophysics (IUCAA), Pune, during the preparation and submission of the first draft of this manuscript.
Author information
Authors and Affiliations
Corresponding author
Additional information
Km Nitu Rai has a doctorate from IISER TVM India and is currently working as a Research Associate at ARIES Nainital.
Soumen Basak received his PhD from IMSc, Chennai. In July 2017, Dr. Basak joined the School of Physics at IISER TVM as a faculty. He was part of the team that was honored with the prestigious Gruber Cosmology Prize in 2018.
Subrata Sarangi is a Physics teacher, having taught for about 30 years at universities such as BITS at Pilani, ICFAI University, KIIT Deemed University, and Centurion University. His areas of research interest include Nuclear Physics, Materials Science, Astronomy, and Astrophysics.
Prasenjit Saha is an astrophysicist at the University of Zurich, Switzerland.
Rights and permissions
About this article
Cite this article
Rai, K.N., Basak, S., Sarangi, S. et al. Interference with (Pseudo) Thermal Light. Reson 30, 45–57 (2025). https://doi.org/10.1007/s12045-025-1729-x
Published:
Version of record:
Issue date:
DOI: https://doi.org/10.1007/s12045-025-1729-x