Applications of two-photon processes in semiconductor photonic devices: invited review

Abstract

Semiconductor photonics is an advanced field, both from fundamental and applicative points of view, aimed at the integration of the unique features of optical communications and quantum optics with the miniaturization and controllability of semiconductors. Many classical and quantum applications may benefit from interaction between optical signals, usually implemented by nonlinear optical processes of various orders. The efficiency of such processes in semiconductors is being constantly enhanced, assisted by the progress in ultrashort laser pulses and ultra-sensitive detectors, enabling practical devices. In this review, the lowest order of nonlinear interactions-the two-photon processes in semiconductors-are discussed, and their applications to a variety of novel classical and quantum configurations are reviewed.

State‐of‐the‐art all‐silicon sub‐bandgap photodetectors at telecom and datacom wavelengths

“…The result of these research processes is that all‐Si PDs are now capable of performance that is competitive with Ge‐based devices, while also offering distinctive characteristics that are potentially advantageous. Indeed, the instantaneous non‐linearity provided by TPA has lead to both commercially available autocorrelators and high‐speed components such as optical demultiplexers ‐ and sampling for use in ultra‐high capacity optical time‐division multiplexed systems . Moreover, very recently, the advantages of all‐Si PDs based on BDA have been demonstrated in the 2 μm wavelength region, where Ge has negligible absorption .…”

Active 2D materials for on-chip nanophotonics and quantum optics

“…These traces show a clear dip at Δt = 0 with a width corresponding to the detector's carrier relaxation time of ~ 3 ps. In this device, strong non-linear photoresponse at low peak power could enable a more efficient on-chip autocorrelator compared with existing autocorrelators based on free-space parametric frequency conversion and two-photon absorption in semiconductor waveguides [71][72][73], while keeping a footprint of only 40 μm in length. The femtosecond thermalization of graphene's hot electrons suggests that the timing resolution of the on-chip autocorrelator is possibly down to sub-50 fs [74].…”

Nondegenerate two-photon absorption in GaAs/AlGaAs multiple quantum well waveguides

“…Applications of ND-2PA include detection [1], imaging [2], and all-optical switching [3]. Inverting carrier populations can also transform ND-2PA into nondegenerate two-photon gain [4][5][6], which is critical for realizing a two-photon semiconductor laser [7][8][9]. Waveguides are especially interesting for nonlinear optical applications because they enable strong effects through long interaction lengths.…”