Master Oscillator Power Amplifier, a layout that separates the job of setting pulse shape, wavelength and linewidth, done by a small seed oscillator, from the job of making power, done by one or more amplifiers. Pulsed fiber lasers for marking use MOPA designs so pulse duration and repetition rate can be set independently. The cost is more ASE management and isolators between stages.
It's a MOPA marker, so you can dial pulse width from 2 to 200 ns and the rep rate separately.
Also heard as
- master oscillator power amplifier
- MOFA
Related terms
Seed
The low-power laser whose output is amplified in a MOPA or amplifier chain, setting its timing and spectrum.
EDFA
Erbium-Doped Fiber Amplifier: the optical amplifier that boosts signals near 1550 nm without converting them to electronics.
Gain saturation
The drop in an amplifier's gain as the signal grows strong enough to deplete the stored inversion.
Optical isolator
A one-way valve for light that passes a beam forward and blocks reflections from returning to the laser.
Fiber laser
A laser whose gain medium is an optical fiber with a rare-earth-doped core, pumped by diodes.