The slope of output power plotted against pump power above threshold, given as a percentage for optical pumping or in W/A for diodes. Well-designed Yb fiber lasers reach 80 percent or more, close to the quantum-defect limit, while diode-pumped solid-state lasers typically run 30 to 60 percent. It is a better measure of a laser's health than raw output power because it separates loss from threshold effects.
Slope efficiency on the new fiber is 82 percent, so the splice to the FBG is clean and the pump's all getting absorbed.
Also heard as
- differential efficiency
- slope
Related terms
Lasing threshold
The pump level at which gain exactly balances resonator losses and laser output begins.
Pump
The energy source that excites a gain medium, or the act of supplying it, usually with diodes, flashlamps or current.
Fiber laser
A laser whose gain medium is an optical fiber with a rare-earth-doped core, pumped by diodes.
Kink
A sudden bend or step in a laser diode's power-versus-current curve, usually a sign of mode switching.