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Nonlinear Optical Properties of Semiconductors, Principles, and Applications
Published in Inamuddin, Mohd Imran Ahamed, Rajender Boddula, Tariq Altalhi, Optical Properties and Applications of Semiconductors, 2023
Muhammad Rizwan, Aleena Shoukat, Asma Ayub, Iqra Ilyas, Ambreen Usman, Seerat Fatima
Two-photon absorption (TPA) is a third-order mechanism in NLO that is connected with extended π-conjugated electronic structures and charge carrier properties, which can be measured ultimately by two-photon absorption radiation fluorescence (TPF). Organic composites that exhibit TPA show promising frequency up transition lasing, optical signal regulating, 3D fluorescence, 3D optical computing, 3D digital image microfabrication, and photothermal therapy. TPA is a phenomenon in which molecule absorbs two photons at the same time and is naturally weak at a usual intensity of light (Winter and Shroff 2014).
Determination of the contributions of degenerate and non-degenerate two-photon absorption response in silicon avalanche photodiode for infrared photon detection
Published in Journal of Modern Optics, 2020
Guangjian Xu, Xinyi Ren, Qucheng Miao, Ming Yan, Haifeng Pan, Xiuliang Chen, Guang Wu, E Wu
In the TPA process, if the energies of the two absorbed photons are the same, it is the so-called the degenerate two-photon absorption (D-TPA), otherwise it is the so-called the non-degenerate two-photon absorption (ND-TPA). The TPA effect of semiconductors has been studied in different materials and structures. It has been experimentally demonstrated that the TPA effect can lead to an enhancement factor up to 100–1000 in direct-bandgap semiconductors [10]. The extremely ND-TPA in GaN photodiodes is utilized to perform scanned imaging of three-dimensional structures by infrared femtosecond laser pulse illumination [23]. The TPA effect in the commercial In0.81Ga0.19As photodetector has been investigated to extend the nonlinear optical response to 4500 nm [24]. In addition, the nanostructured indium phosphide (InP) photodiode has been designed to detect the infrared light at room temperature using ND-TPA, and owing to the nanostructure, the photocurrent shows a gain of 24 with respect to the bulk response of InP [25]. The TPA effect has also been considered in silicon materials. For instance, a full band structure of TPA in bulk silicon has been theoretically calculated [26], and the D-TPA and Kerr coefficient of bulk Si for wavelength at 850 nm to 2200 nm has been measured in the experiment [27]. But the specific contribution value of D-TPA and ND-TPA effects in silicon photodetectors for infrared light detection has not been investigated so far as we known.