Dual-frequency injection-locked nanosecond pulsed laser with arbitrary combination of two oscillation frequencies.

We report a dual-frequency injection-locked nanosecond pulsed laser oscillating at an arbitrary combination of two frequencies over the broad gain range of a Ti:sapphire laser. This performance is achieved by employing two techniques. One involves introducing two different modulation frequencies to discriminate electronically the error signals, which are used for locking the two seed frequencies to the forced oscillator. The other is a cavity design that enables us to sweep the cavity length without distorting the alignment or changing the spatial mode of the cavity. The difference frequencies in a pair of single-frequency nanosecond pulses can be selected continuously from less than 1 GHz to tens of THz without modifying the laser configuration.