High-sensitivity 10 Gbps Ge-on-Si photoreceiver operating at lambda approximately 1.55 microm.

Area of Science:

• Optoelectronics
• Semiconductor Devices
• Photonics

Background:

• Photoreceivers are crucial components in optical communication systems.
• Germanium-on-silicon (Ge-on-Si) technology offers a cost-effective alternative to III-V materials.
• High-sensitivity photoreceivers are needed for high-speed data transmission.

Purpose of the Study:

• To present a high-sensitivity photoreceiver utilizing a vertical-illumination-type 100% Ge-on-Si photodetector.
• To evaluate the performance characteristics of the fabricated Ge-on-Si photodetector and photoreceiver.
• To demonstrate the potential of Ge-on-Si technology as a replacement for III-V photoreceivers.

Main Methods:

• Fabrication of a p-i-n photodetector using 100% Ge-on-Si epitaxy.
• Characterization of the photodetector's bandwidth and responsivity at 1.55 microm wavelength.
• Packaging the Ge photodetector into a TO-can photoreceiver for sensitivity measurements.
• Testing the photoreceiver's sensitivity at a 10 Gbps data rate with a bit error rate (BER) of 10(-12).

Main Results:

• The fabricated p-i-n photodetector exhibited a -3 dB bandwidth of 7.7 GHz.
• Responsivity reached 0.9 A/W at 1.55 microm, corresponding to 72% external quantum efficiency.
• The packaged Ge photoreceiver achieved a sensitivity of -18.5 dBm at 10 Gbps for a BER of 10(-12).

Conclusions:

• The 100% Ge-on-Si photoreceiver demonstrates high sensitivity and bandwidth suitable for optical communications.
• This cost-effective Ge-on-Si technology presents a viable alternative to expensive III-V photoreceivers.
• The results highlight the potential for widespread adoption of Ge-on-Si in next-generation optical networks.