To seed an amplifier means to provide a source of low energy, typically high repetition rate, pulses which are injected into an optical amplifier to increase the energy of selected pulses by several orders of magnitude. The repetition rate of the amplified pulses is reduced in favour of the high energy per pulse. In large amplifier chains, the seed oscillator may only be a small, but very important system component right at the starting point of the optical chain, as it is the initial source of photons, playing crucial part in the overall performance of the amplifier system.
Seeding an amplifier imposes special demands onto the oscillator used. The oscillator needs to provide an excellent beam pointing stability of a clean high contrast low noise pulse train with a stable, reproducible spectrum without spatial chirp as one prerequisite for easy everyday operation of amplifiers.
The venteon/gecco series of oscillators are built on a monolithic setup for maximum mechanical stability. The prismless cavity based on dispersive compensating mirrors (DCM) enables a most stable optical design offering a high beam pointing stability in the absence of dispersive elements based on angular chirp. DCM offer advanced dispersion engineering resulting in the output of clean high contrast broad bandwidth pulses with no spatial chirp, ideally suited for input into an amplifier.
Ease of use is ensured by full automation and operation via the controller of the seed oscillator, with its mechanism to self-start, monitor and maintain its mode locking. The compact monolithic housing with selected motorized parts inside provide long-term stability as well as the capability for remote service, should it be needed. For 24/7 applications that demand least amount of down time in case, the oscillators are principally field serviceable.
The venteon and gecco series of oscillators has a history of being supplied on an OEM basis, or into large research facilities serving special demands such as repetition rate stabilisation to synchrotrons.
Even most advanced seeding needs such as providing two colour jitter free pulses for seeding OPCPA systems can be served right from the compact oscillator platform.