AlInGaAs MQW Transceiver with Electro-optic Modulation Characteristics for Free-Space Optical Communication and Sensing

Abstract

Integrated transceivers with electro-optic modulation characteristics are valuable for free-space optical communications and sensing. We propose an AlInGaAs multiple quantum well (MQW) transceiver with electro-optic modulation characteristics over a broad spectral range. Two identical AlInGaAs MQW diodes on a single wafer are used to transmit and receive optical signals and provide obvious electro-optic modulation for broad-spectrum light. The photocurrent modulation ratio reaches 13.9 and 11.3 for white light and 1550 nm infrared light, respectively, with varying bias voltages. The transceiver can identify environmental changes and forward electrical signals with different frequencies in the form of superimposed optical signals.

Chiral Diketopyrrolopyrrole-Based Conjugated Polymers with Intramolecular Rotation–Isomeric Conformation Asymmetry for Near-Infrared Circularly Polarized Light-Sensing Organic Phototransistors

“…In particular, solution-processable chiral π-conjugated systems exhibit distinctive chiroptical activity, such as high optical rotatory power and strong circular dichroism (CD) in films, which makes them prospective candidate for chiral optoelectronics . In addition, they have unique advantages in that their rational molecular design and synthesis provide various possibilities for constructing molecular and supramolecular chirality and enable precise manipulation of the spectral response via the tunable frontier energy levels. , Thus, the application range of CP light can be broadened to various future real-world optoelectronic and photonic systems that function at near-infrared (NIR) bands, such as free-space optical communication, LiDAR, night-vision, and health monitoring devices, among others. − The archetypal chiral π-conjugated materials have a nonplanar fused aromatic skeleton , or asymmetric substituents with an enantiopure chiral center, , leading to symmetry breaking of molecular orbitals through an intrinsically helical configuration and/or structural chirality. In chiral and fully π-conjugated small molecules such as helicene derivatives having a spiral structure of fused carbocyclic or heterocyclic rings, outstanding chiroptical activity (dissymmetry ≈ 10 –2 ) arises from the inherent chirality of the helical-shaped chromophore with a large torsional angle and twisted conformation.…”