Optical detection and modulation at 2µm-25µm in silicon

Abstract

Abstract:Recently the 2μm wavelength region has emerged as an exciting prospect for the next generation of telecommunications. In this paper we experimentally characterise silicon based plasma dispersion effect optical modulation and defect based photodetection in the 2-2.5μm wavelength range. It is shown that the effectiveness of the plasma dispersion effect is dramatically increased in this wavelength window as compared to the traditional telecommunications wavelengths of 1.3μm and 1.55μm. Experimental results from the defect based photodetectors show that detection is achieved in the 2-2.5μm wavelength range, however the responsivity is reduced as the wavelength is increased away from 1.55μm. Kaertner, and T. M. Lyszczarz, "CMOS-compatible all-Si high-speed waveguide photodiodes with high responsivity in near-infrared communication band," IEEE Photon.

Ar+-Implanted Si-Waveguide Photodiodes for Mid-Infrared Detection

“…In particular, the Ar + devices show a higher optical absorption coefficient and higher thermal stability than similarly structured and implanted Si + devices while retaining similar internal quantum efficiencies (IQE). Our devices show a peak responsivity between 20 and 25 mA/W for a 3 mm long PD, using a reverse bias of 5 V; our results compare very favorably with the best performing Si + -implanted devices in the literature [8,[12][13][14], and nearly double the peak responsivity seen for similar Si + -implanted devices operating under the same conditions.…”

“…For example, recent advancements in thulium-doped fiber amplifiers have made possible the needed laser sources while the development of numerous passive Si photonic components working at wavelengths beyond 1.55 µm have extended basic Si circuits into the mid-infrared (2-2.5 µm) [6][7][8][9][10][11][12][13][14]. However, other devices remain to be fully developed.…”

“…Applications for these detectors can range from their use as auto-correlators [9] to fast power monitors [10]. Responsivities between 5 mA/W and 300 mA/W have been achieved [8,[12][13][14]. To date, the majority of these PDs have relied upon the Si divacancy defect for detection.…”

Mid-infrared integrated photonics on silicon: a perspective

“…At 2.165 μm, the electro-optic modulator achieved an impressive V π · L of 0.012 V cm, an extinction ratio of 23 dB, and modulation bitrates up to 3 Gbps [156]. Improved efficacy of FCA modulation at longer wavelength was experimentally validated in the 2-2.5-μm and 3.8-μm bands [157,159].…”

“…Both electro-optic and electroabsorption modulation exploiting free carrier effects have been implemented in the 2-2.5-μm band in SOI devices [156,157], and all-optical modulation based on FCA was also demonstrated in Ge-on-Si waveguides [158]. At 2.165 μm, the electro-optic modulator achieved an impressive V π · L of 0.012 V cm, an extinction ratio of 23 dB, and modulation bitrates up to 3 Gbps [156].…”