Semiconductor laser oscillator

1. A semiconductor laser oscillator comprising:

a diode source comprising a plurality of banks, in which one bank comprises a plurality of laser diodes connected in series, wherein

the diode source comprises a wavelength lock configured to lock to a plurality of wavelengths, and

the semiconductor laser oscillator further comprises a controller configured to control input currents to the plurality of laser diodes of each of the plurality of banks individually in correspondence to a characteristic of a wavelength locking efficiency, and to control an output of the diode source as a whole to a required output,

wherein the plurality of banks comprise at least a first bank for which the wavelength locking efficiency at a time of low current where an input current is from 0 to a predetermined value is in a first state, and a second bank for which the wavelength locking efficiency at the time of low current is in a second state that is lower than the first state, and

the controller controls an output of the second bank to be 0 while an output required for the diode source as a whole is from 0 to a predetermined value.

2. The semiconductor laser oscillator according to claim 1 , wherein the laser diodes are single emitter laser diodes.

3. The semiconductor laser oscillator according to claim 1 , wherein the laser diodes are laser diode modules in which a plurality of single emitter laser diodes are spatially coupled.

4. The semiconductor laser oscillator according to claim 1 , wherein the laser diodes are diode laser bars.

5. The semiconductor laser oscillator according to claim 1 , wherein the laser diodes are laser diode modules in which a plurality of diode laser bars are spatially coupled.