Reduction of relative intensity noise and improvement of spur-free dynamic range of an injection locked VCSEL

Abstract

Optical injection locking has been demonstrated to increase the laser bandwidth and reduce the laser chirp and distortion. In this paper, we report the first direct RIN measurement of an injection-locked laser for different injection conditions. A record 3/sup rd/ harmonic SFDR of 111 dB-Hz/sup 2/3/ at 2 GHz was also demonstrated for a directly modulated VCSEL with this technique. To conclude, the RIN spectra of an injection-locked VCSEL were studied for different injection conditions. More than 10 dB reduction of the RIN can be obtained at the free-running resonance frequency. A record SFDR value at 2 GHz was also reported using the injection locking technique.