The oscillator at the front of an amplified system, such as a DFB diode, a mode-locked fiber oscillator or a Ti:sapphire oscillator feeding a regen. Its wavelength, linewidth, pulse shape and timing pass straight through to the output, so a noisy seed means a noisy laser. Used as a verb too: to seed an amplifier, or a seeded versus unseeded laser.
Seed's down to 8 milliwatts after the isolator, that's below spec for the preamp, find out what's eating it before we pump.
Interlocks on high-gain amplifiers should watch seed power and shut the pumps down within microseconds when it drops.
Also heard as
- seed laser
- seeder
Related terms
MOPA
Master Oscillator Power Amplifier: a low-power seed laser followed by amplifier stages that bring it to full power.
Regen
Clipped form of regenerative amplifier, the cavity that traps a seed pulse for many passes of gain before releasing it.
ASE
Amplified Spontaneous Emission: random spontaneous photons amplified in a gain medium, a broadband noise background.
Linewidth
The spectral width of a single-frequency laser's output, usually given in Hz, kHz or MHz at half maximum.