The KMLabs Halcyon™ repetition-rate stabilized oscillator is popular with customers who need to synchronize oscillator laser pulses with pulses from another laser or with a synchrotron. Electronics included with the Halcyon lock its output to the customer’s reference signal and can provide timing jitter of less than 150 fs. Stabilization of the repetition rate is achieved through multiple features including a temperature-stabilized breadboard, a motorized stage for coarse feedback, and a small piezo-mounted mirror for fast feedback. The KMLabs team works closely with each Halcyon customer to ensure that the system meets their specific needs. Due to the flexible design of the Halcyon™, it can lock to reference signals over a very wide range: 75 MHz to 4 GHz.