Monolithically integrated optically-pumped edge-emitting semiconductor laser

An optical device comprising:

• a substrate;
• a semiconductor edge-emitting signal laser disposed on the substrate for emitting laser light, the edge-emitting signal laser having a signal laser optical cavity comprising an active region at which laser light emission occurs, a cross-section of the signal laser active region being dimensioned to produce a single mode laser light output suitable for efficient coupling to single mode optical fibers:
• and
• at least one semiconductor pump laser also disposed on the substrate, the pump laser having a pump laser optical cavity comprising an active region, the pump laser being monolithically integrated with the signal laser such that the pump laser optical cavity lies in a direction substantially perpendicular to that of the signal laser optical cavity and substantially in the same plane as that of the signal laser optical cavity substantially parallel to the substrate, the pump laser providing optical pumping of the signal laser along a signal laser active region length such that laser light output from the signal laser is substantially in the same plane as laser light output from the pump laser and substantially parallel to the substrate.