Investigation of pulse-to-pulse timing jitter in an ultrafast Cr:LiSAF laser for synchronization of radiation pulses

Abstract

Timing jitter is closely related to the phase noise of ultrafast laser pulse train under different mode-locking regimes. Investigations have been made towards timing jitter for pulse-to-pulse Cr:LiSAF femtosecond laser, for usage as a seed laser in synchrotron light source. The laser produced about 180 fs of pulses with an 83.27 MHz pulse repetition rate, which corresponds to a 1.80 m cavity length. Mode-locking was passively achieved using semiconductor saturable absorber mirror (SESAM) optimized for low threshold and stability operation. Active timing-jitter stabilization to an external high precision electronic oscillator was attained with a cavity length control loop using a piezoelectric actuator. Phase noise detection has been evaluated using a timing stabilizer system (CLX-1100) and a phase detector (AD8302). According to the results, the AD8302 phase detector has superior timing jitter sensitivity than the CLX-1100 timing stabilizer system. Ultra low-noise oscillator was introduced to improve the performance of the CLX-1100 timing stabilizer system, which has been evaluated from the phase noise of spectral density and reflected in the root mean square timing jitter. The low timing jitter of the laser pulses was sufficient to accomplish the synchrotron of the radiation source.