title: High-accuracy photoreceiver frequency response measurements at 1.55 µm by use of a heterodyne phase-locked loop.
abstract: We demonstrate a high-accuracy heterodyne measurement system for characterizing the magnitude of the frequency response of high-speed 1.55 µm photoreceivers from 2 MHz to greater than 50 GHz. At measurement frequencies below 2 GHz, we employ a phase-locked loop with a double-heterodyne detection scheme, which enables precise tuning of the heterodyne beat frequency with an RF synthesizer. At frequencies above 2 GHz the system is operated in free-run mode with thermal tuning of the laser beat frequency. We estimate the measurement uncertainties for the low frequency range and compare the measured high-frequency response of a photoreceiver to a measurement using electro-optic sampling.
authors: National Institute of Standards and Technology, 325 Broadway, Boulder, CO 80305, USA. tasshi@boulder.nist.gov
authors: Tasshi
authors: T
authors: Dennis
authors: Paul D
authors: PD
authors: Hale