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Calculation of the impulse response and phase noise of a high-current photodetector using the drift-diffusion equations



Franklyn Quinlan, Seyed Ehsan Jamali Mahabadi, Shaokang Wang, Thomas F. Carruthers, Curtis R. Menyuk, Meredith N. Hutchinson, Jason D. McKinney, Keith J. Williams


We describe a procedure to calculate the impulse response and phase noise of high-current photodetectors using the drift-diffusion equations while avoiding computationally expensive Monte Carlo simulations. We apply this procedure to a modified uni-traveling-carrier (MUTC) diode. In our approach, we first use the full drift-diffusion equations to calculate the steady-state photodetector parameters. We then perturb the generation rate as a function of time to calculate the impulse response. We next calculate the fundamental shot noise limit and cut-off frequency of the device. We find the contributions of the electron, hole, and displacement currents. We calculate the phase noise of an MUTC photodetector. We find good agreement with experimental and Monte Carlo simulation results. We show that phase noise is minimized by having as square an impulse response as possible. Since, our approach is much faster computationally than Monte Carlo simulations, we are able to carry out a broad parameter study to optimize the device performance. We propose a new optimized structure with less phase noise and reduced nonlinearity.
Optics Express


electro-optics, phase noise, photodetection, timing jitter


Quinlan, F. , Mahabadi, S. , Wang, S. , Carruthers, T. , Menyuk, C. , Hutchinson, M. , McKinney, J. and Williams, K. (2019), Calculation of the impulse response and phase noise of a high-current photodetector using the drift-diffusion equations, Optics Express, [online], (Accessed June 25, 2024)


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Created February 4, 2019, Updated June 7, 2024