Injection locking Q-switched and Q-switched cavity dumped CO₂ lasers for extreme UV generation

摘要

A CO₂ laser reference oscillator (RO) can provide injection seeding to a Q-switched (QS) or Q-switched cavity dumped (QSCD) CO₂ laser, where the output frequency of the RO laser is locked to the peak of the laser line by the use of appropriate electronics to dither one of the resonator mirrors of the reference oscillator. This injected radiation seeds the radiation building up within the Q-switched laser cavity, such that the oscillating frequency favors the wavelength of the injected radiation. An electronic feedback control circuit can be used to lock an axial mode of the Q-switched laser to line center. The change in build-up time of the pulses within the QS laser can be used to maintain cavity length at a value that enables oscillating at the peak of the same laser line that is injected into QS laser.