ANORDNING FOR STABILISERING AV UTGANGSKARAKTERISTIKORNA HOS EN INJEKTIONSLASER

Apparatus for stabilizing output characteristicss of an injection laser by monitoring the output level of the laser corresponding to the d.c. bias level and maintaining this level constant at a value which corresponds substantially to the laser being biased at or very close to threshold. The apparatus has a light sensitive device for producing an electrical signal corresponding to the d.c. bias level of the laser. The electrical signal is compared with a reference signal to produce a further signal which is applied to d.c. bias control means for the laser. The d.c. bias control means responds to the further signal to adjust the d.c. bias level such that the d.c. light output level remains substantially at a predetermined level. The mean or peak output of the laser can be controlled in a similar manner.