Optimizing the linearity in high-speed photodiodes

Abstract

Analog photonic links require high-fidelity, high-speed optical-to-electrical conversion for applications such as radio-over-fiber, synchronization at kilometer-scale facilities, and low-noise electronic signal generation. Photodetector nonlinearity is a particularly vexing problem, causing signal distortion and excess noise, especially in systems utilizing ultrashort optical pulses. Here we show that photodetectors designed for high power handling and high linearity can perform optical-to-electrical conversion of ultrashort optical pulses with unprecedented linearity over a large photocurrent range. We also show that the broadband, complex impedance of the circuit following the photodiode modifies the linearity significantly. By externally manipulating the circuit impedance, we extend the detector's linear range to higher photocurrents, with over 50 dB rejection of amplitude-to-phase conversion for photocurrents up to 40 mA. This represents a 1000-fold improvement over state-of-the-art photodiodes and significantly extends the attainable microwave power by a factor of four. As such, we eliminate the long-standing requirement in ultrashort pulse detection of precise tuning of the photodiode's operating parameters (average photocurrent, bias voltage or temperature) to coincide with a nonlinearity minimum. These results should also apply more generally to reduce nonlinear distortion in a range of other microwave photonics applications.

References in corpus (9)

• Generation of Ultrastable Microwaves via Optical Frequency Division
• Optical frequency comb technology for ultra-broadband radio-frequency photonics
• Photonic microwave signals with zeptosecond level absolute timing noise
• An Optical Fibre Pulse Rate Multiplier for Ultra-low Phase-noise Signal Generation
• Characterization of Power-to-Phase Conversion in High-Speed P-I-N Photodiodes
• Analysis of shot noise in the detection of ultrashort optical pulse trains
• Amplitude to phase conversion of InGaAs pin photo-diodes for femtosecond lasers microwave signal generation
• Optical amplification and pulse interleaving for low noise photonic microwave generation
• Suppression of amplitude-to-phase noise conversion in balanced optical-microwave phase detectors

Cited by in corpus (4)

• Coherent Optical Clock Down-Conversion for Microwave Frequencies with 10-18 Instability
• Frequency Stable Microwave Sapphire Oscillators
• Noise Suppression with Cryogenic Resonators
• Large-scale photonic chip based pulse interleaver for low-noise microwave generation