III-V/silicon photonic integrated circuits for spectroscopic sensing in the 2um wavelength range

Abstract

III-V/silicon photonic integrated circuits (ICs) promise to enable low cost and miniature optical sensors for trace-gas detection, bio-sensing and environmental monitoring. A lot of these applications can benefit from the availability of photonic ICs beyond the telecommunication wavelength range. The 2 µm wavelength range is of interest for spectroscopic detection of many important gases and blood constituents. In this contribution we will present 2 µmwavelength-range III-V/silicon photonic ICs consisting of tunable laser sources, photodetectors and silicon waveguide circuits. Silicon waveguides with a loss of ~0.5 dB/cm are obtained in a well-established silicon photonics platform. Based on the waveguides, low insertion loss (2-3 dB) and low crosstalk (25-30 dB) arrayed waveguide gratings (AWGs) are realized for the 2.3 µm wavelength range. Active opto-electronic components are integrated on the photonic IC by the heterogeneous integration of an InP-based type-II epitaxial layer stack on silicon. III-V-on-silicon 2.3 µm range distributed feedback (DFB) lasers can operate up to 25 °C in continuous-wave regime and shows an output power of 3 mW. By varying the silicon grating pitch, a DFB laser array with broad wavelength coverage from 2.28 µm to 2.43 µm is achieved. III-V-on-silicon photodetectors with the same epitaxial layer stack exhibit a responsivity of 1.6 A/W near 2.35 µm. In addition, we also report a 2 µm range GaSb/silicon hybrid external cavity laser using a silicon photonic IC for wavelength selective feedback. A wavelength tuning over 58 nm and side mode suppression ratio better than 60 dB is demonstrated.

A silicon photonics waveguide-coupled colloidal quantum dot photodiode sensitive beyond 1.6 µm

“…Numerous applications, including environmental monitoring, medical diagnostics, and industrial sensing, would profit from photonic chips operating at longer wavelengths. 4,5 Such applications are, however, hampered by the lack of a scalable and cost-effective integrated technology for photodetection beyond 1.6 μm.…”

Compact, Hybrid III-V/Silicon Vernier Laser Diode Operating From 1955–1992 nm

“…(Corresponding author: Hong Wang) (email: ewanghong@ntu.edu.sg) J. X. B. Sia, W. Wang, Z. Qiao, X. Guo, J. Wang and H. Wang are with the School of Electrical and Electronic Engineering, Nanyang Technological configured external cavity lasers (ECL) have also indicated wide spectral operating range, but however, the applicationspace of these class of lasers are limited by their bulk [3], as well as higher vulnerability to environmental vibrations [4]. The challenge is for the development of a solid state-based laser diode with a compact footprint, good performance (i.e., tuning range, output power) that can be manufactured in a scalable, high-yield and low-cost process.…”

Silicon ring resonator-coupled Mach–Zehnder interferometers for the Fano resonance in the mid-IR

“…In this context, research effort has been carried out in order to extend the operation of silicon photonic devices from the near-infrared to the mid-IR wavelength range. Actually, several results on state-of-the-art mid-IR lasers and photodetectors have been recently reported in the literature [2][3][4] as well as passive and active photonic integrated devices successfully demonstrated, i.e. multimode interferometers, ring resonator, MZIs, spectrometers, modulators, multiplexers and (de)multiplexers, fabricated on silicon and germanium technology platforms and operating at wavelengths up to ~ 7.5 µm [5][6][7][8][9][10][11][12][13].…”