Temporal and frequency response of avalanche photodiodes from noise measurements

Abstract

This paper describes a method of obtaining the temporal and frequency response of avalanche photodiodes (APD) by performing simple noise measurements. From the measured noise spectrum and by using the Hilbert transformation technique, the complex transfer function of the detector is determined. response can then easily be calculated by means of fast Fourier transforming. The method has been applied on a high speed APD, with a bandwidth of ~2 GHz, and on a relatively slow APD, with a bandwidth of 0.2 GHz, to calculate the pulse response from a short optical pulse. The calculated pulse width for the fast APD was 215 psec, and the corresponding measured width was 210 psec, while for the slow APD the calculated and the measured widths both were 3.1 nsec. Also the shapes of the pulse responses showed excellent agreement. The method depends on the essentially identical frequency response of an APD and associated circuits for noise due to steady-state illumination and for a signal.

A computer system for analysis of high capacity components in optical-fiber links

“…Instead we have taken advantage of the similarities in the frequency behavior of the transfer function G(jw) and the shot-noise power spectrum νΙ(ω). The frequency behavior of the noise spectrum can be expressed as [19] ν 2 η (ω) ~ |Λ/(/ω)| 2 |Ζ)(/·ω)| 2 |ΖΟ·ω)| 2…”

“…With a time-domain reflectometry (TDR) measurement, shown in Fig. 2(b), we can determine the equivalent circuit parameters by fitting a calculated step re flection to the step reflection measured with the sampling os cilloscope [19]. This will enable us to determine whether the APD is limited by the RC time, the transit time, or the mul tiplication time.…”

“…Minimum phase be havior is expected since the gain factor, the delay factor, and the transfer function of the equivalent circuit all show mini mum phase behavior [16], [17], [19]. Knowing both magni tude and phase of the transfer function, one can calculate the electrical output arising from any optical input using FFT techniques.…”

Measuring the Frequency Response of Photodiode Using Phase-Modulated Interferometric Detection

“…In order to measure the frequency response of photodiodes, a variety of techniques have been demonstrated in the past decade, including pulse spectrum analysis [1], optical heterodyne methods [2]- [6], the optical intensity noise technique [7], [8], and the swept frequency method by external modulation [9]. Among these methods, the impulse response analysis method is a time domain method which needs short pulse laser and high sampling rate oscilloscope.…”

Bandwidth measurements of ultrahigh-frequency optical detectors using the interferometric FM sideband technique

“…As the bandwidth of these detectors reaches beyond 100 GHz [l], it becomes increasingly difficult to measure their frequency response. Swept frequency measurements require either an intensity modulated laser or an external modulator both with a known response greater than that of the detector [2]; measurement of the shot noise frequency spectrum is difficult due to extremely low signal levels [3]; time domain measurements require picosecond optical pulses and can be affected by sampling and computational errors [4], [5]; and the beat frequency method requires two narrow linewidth (usually external cavity) semiconductor lasers with excellent temperature control [6], [7].…”