High-sensitivity Photoreceiver Research Articles

High-performance photoreceivers based on vertical-illumination type Ge-on-Si photodetectors operating up to 43 Gb/s at λ~1550nm

We present high-sensitivity photoreceivers based on a vertical- illumination-type 100% Ge-on-Si p-i-n photodetectors (PDs), which operate up to 50 Gb/s with high responsivity. A butterfly-packaged photoreceiver using a Ge PD with 3-dB bandwidth (f(-3dB)) of 29 GHz demonstrates the sensitivities of -10.15 dBm for 40 Gb/s data rate and -9.47 dBm for 43 Gb/s data rate, at BER of 10(-12) and λ ~1550 nm. Also a photoreceiver based on a Ge PD with f(-3dB)~19 GHz shows -14.14 dBm sensitivity at 25 Gb/s operation. These results prove the high performance levels of vertical-illumination type Ge PDs ready for practical high-speed network applications.

High-sensitivity 10 Gbps Ge-on-Si photoreceiver operating at λ ~155 μm

We present a high-sensitivity photoreceiver based on a vertical- illumination-type 100% Ge-on-Si photodetector. The fabricated p-i-n photodetector with a 90 microm-diameter mesa shows the -3 dB bandwidth of 7.7 GHz, and the responsivity of 0.9 A/W at lambda approximately 1.55 microm, corresponding to the external quantum efficiency of 72%. A TO-can packaged Ge photoreceiver exhibits the sensitivity of -18.5 dBm for a BER of 10(-12) at data rate of 10 Gbps. This result proves the capability of a cost-effective 100% Ge-on-Si photoreceiver which can readily replace the III-V counterparts for optical communications.

High sensitivity photo receiver design

The paper describes low noise preampliers designed for optical detectors Analysis of operating conditions affecting signal-to-noise ratio has been carried out. Each preamplier was carefully optimized to work with particular type of the detector.

InGaAsP channel HFET's on InP for OEIC applications

A model for the calculation of the input noise of a high impedance photoreceiver is proposed, taking into account the contributions of low-frequency characteristics of the FET. Simulations based on this approach show that excess gate leakage current and low-frequency excess noise, usually observed in InGaAs channel FET's, strongly penalize the photoreceiver sensitivity for low to medium data rates. New InGaAsP channel HFET's have been developed and fabricated to solve those problems, dc measurements on 1/spl times/100 /spl mu/m/sup 2/ gate HFET's show good I/sub ds/-V/sub ds/ characteristics with associated gate leakage currents lower than 200 nA. Promising ft of 18 GHz and f/sub max/ of 40 GHz have been recorded on 0.5/spl times/200 /spl mu/m/sup 2/ gate transistors. Low-frequency gate and channel noise measurements demonstrate the suitability of InGaAsP channel HFET structure and technology for low noise applications. A hybrid pin-HFET high impedance photoreceiver has been assembled with a 1/spl times/150 /spl mu/m/sup 2/ gate transistor. A very close agreement is found between photoreceiver input noise predicted by our model and experimental results. Record sensitivities of 34.8 dBm at 622 Mbit/s and -28.7 dBm at 2.5 Gbit/s are inferred from noise measurements, confirming the strong potential of InGaAsP channel HFET's for the fabrication of high sensitivity photoreceivers operating at moderate data rates.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>