InP-Based Active and Passive Components for Communication Systems at 2 μm

Abstract

> Abstract-Progress on advanced active and passive photonic components that are required for high-speed optical communications over hollow-core photonic bandgap fiber at wavelengths around 2 μm is described in this paper. Single-frequency lasers capable of operating at 10 Gb/s and covering a wide spectral range are realized. A comparison is made between waveguide and surface normal photodiodes with the latter showing good sensitivity up to 15 Gb/s. Passive waveguides, 90°optical hybrids, and arrayed waveguide grating with 100-GHz channel spacing are demonstrated on a large spot-size waveguide platform. Finally, a strong electro-optic effect using the quantum confined Stark effect in strain-balanced multiple quantum wells is demonstrated and used in a Mach-Zehnder modulator capable of operating at 10 Gb/s. Index Terms-Detectors, high bandwidth, lasers, optical communications, optical modulators, quantum confined Stark effect (QCSE).

Key enabling technologies for optical communications at 2000 nm

“…As per Table 1, the measured 3 dB BW is similar as that reported for surface normal devices made from the same material reported in Ref. [31]. These are encouraging results, showing the potential of the device developed here.…”

“…Nevertheless, the value estimated for the edge-coupled device characterized here is more than twice the responsivity of an InGaAs MQW structure reported in Ref. [31] (or 0.3 A/W).…”

“…4. Previous results using this material as photodetector in the surface normal configuration (diameters 30-60 μm) have shown that it can be used to successfully to detect high-speed data signals transmitted at 2000 nm wavelengths [31].…”

Demonstration of High-Speed Optical Transmission at 2 µm in Titanium Dioxide Waveguides

“…Recently, the 2 µm spectral region has been suggested as a new transmission window [5], benefiting from the emergence of thulium-doped fiber amplifiers (TDFA) with broadband and high gain spanning from 1900 to 2100 nm [6]. This has stimulated studies of dedicated photonic components such as InP-based modulators [7,8] or arrayed waveguide gratings [9]. High bit rate communications over distances exceeding one hundred meters have already been successfully demonstrated [10][11][12][13] in low-loss hollow core bandgap photonic fibers designed to present minimal losses around 2000 nm [14] or in solid-core single mode fibers [15].…”

III-V-on-silicon 2-µm-wavelength-range wavelength demultiplexers with heterogeneously integrated InP-based type-II photodetectors

“…Besides, recently improved transmission and amplification capabilities of hollow-core photonic-bandgap fibres promise a new telecommunication window at wavelengths around 2 μm [2]. Therefore, the development of integrated photonic systems for the 2 µm wavelength range has attracted much attention for these applications [3,4]. The integration of a wavelength demultiplexer and photodetector array operating in the 2 µm wavelength range is of key importance for both types of applications.…”