Browsing by Author "Singh, Ravindra P."

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    3D incoherent imaging using an ensemble of sparse self-rotating beams
    (Optics Express, 2023) Bleahu, Andrei-ioan; Gopinath, Shivasubramanian; Kahro, Tauno; Angamuthu, Praveen Periyasamy; Rajeswary, Aravind Simon John Francis; Prabhakar, Shashi; Kumar, Ravi; Salla, Gangi Reddy; Singh, Ravindra P.; Kukli, Kaupo; Tamm, Aile; Rosen, Joseph; Anand, Vijayakumar
    Interferenceless coded aperture correlation holography (I-COACH) is one of the simplest incoherent holography techniques. In I-COACH, the light from an object is modulated by a coded mask, and the resulting intensity distribution is recorded. The 3D image of the object is reconstructed by processing the object intensity distribution with the pre-recorded 3D point spread intensity distributions. The first version of I-COACH was implemented using a scattering phase mask, which makes its implementation challenging in light-sensitive experiments. The I-COACH technique gradually evolved with the advancement in the engineering of coded phase masks that retain randomness but improve the concentration of light in smaller areas in the image sensor. In this direction, I-COACH was demonstrated using weakly scattered intensity patterns, dot patterns and recently using accelerating Airy patterns, and the case with accelerating Airy patterns exhibited the highest SNR. In this study, we propose and demonstrate I-COACH with an ensemble of self-rotating beams. Unlike accelerating Airy beams, self-rotating beams exhibit a better energy concentration. In the case of self-rotating beams, the uniqueness of the intensity distributions with depth is attributed to the rotation of the intensity pattern as opposed to the shifts of the Airy patterns, making the intensity distribution stable along depths. A significant improvement in SNR was observed in optical experiments.
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    Roadmap on computational methods in optical imaging and holography [invited].
    (2024) Rosen, Joseph; Alford, Simon; Allan, Blake; Anand, Vijayakumar; Arnon, Shlomi; Arockiaraj, Francis Gracy; Art, Jonathan; Bai, Bijie; Balasubramaniam, Ganesh M.; Birnbaum, Tobias; Bisht, Nandan S.; Blinder, David; Cao, Liangcai; Chen, Qian; Chen, Ziyang; Dubey, Vishesh; Egiazarian, Karen; Ercan, Mert; Forbes, Andrew; Gopakumar, G.; Gao, Yunhui; Gigan, Sylvain; Gocłowski, Paweł; Gopinath, Shivasubramanian; Greenbaum, Alon; Horisaki, Ryoichi; Ierodiaconou, Daniel; Juodkazis, Saulius; Karmakar, Tanushree; Katkovnik, Vladimir; Khonina, Svetlana N.; Kner, Peter; Kravets, Vladislav; Kumar, Ravi; Lai, Yingming; Li, Chen; Li, Jiaji; Li, Shaoheng; Li, Yuzhu; Liang, Jinyang; Manavalan, Gokul; Mandal, Aditya Chandra; Manisha, Manisha; Mann, Christopher; Marzejon, Marcin J.; Moodley, Chané; Morikawa, Junko; Muniraj, Inbarasan; Narbutis, Donatas; Ng, Soon Hock; Nothlawala, Fazilah; Oh, Jeonghun; Ozcan, Aydogan; Park, YongKeun; Porfirev, Alexey P.; Potcoava, Mariana; Prabhakar, Shashi; Pu, Jixiong; Rai, Mani Ratnam; Rogalski, Mikołaj; Ryu, Meguya; Choudhary, Sakshi; Salla, Gangi Reddy; Schelkens, Peter; Şener, Sarp Feykun; Shevkunov, Igor; Shimobaba, Tomoyoshi; Singh, Rakesh K.; Singh, Ravindra P.; Stern, Adrian; Sun, Jiasong; Zhou, Shun; Zuo, Chao; Zurawski, Zack; Tahara, Tatsuki; Tiwari, Vipin; Trusiak, Maciej; Vinu, R. V.; Volotovskiy, Sergey G.; Yılmaz, Hasan; Barbosa De Aguiar, Hilton; Ahluwalia, Balpreet S.; Ahmad, Azeem
    Computational methods have been established as cornerstones in optical imaging and holography in recent years. Every year, the dependence of optical imaging and holography on computational methods is increasing significantly to the extent that optical methods and components are being completely and efficiently replaced with computational methods at low cost. This roadmap reviews the current scenario in four major areas namely incoherent digital holography, quantitative phase imaging, imaging through scattering layers, and super-resolution imaging. In addition to registering the perspectives of the modern-day architects of the above research areas, the roadmap also reports some of the latest studies on the topic. Computational codes and pseudocodes are presented for computational methods in a plug-and-play fashion for readers to not only read and understand but also practice the latest algorithms with their data. We believe that this roadmap will be a valuable tool for analyzing the current trends in computational methods to predict and prepare the future of computational methods in optical imaging and holography.