Patent ID: 6717971
Filing Date: 2004-04-06
Classification: H01S

Abstract:
A semiconductor laser device comprising:a substrate, a first cladding layer formed on the substrate, a core or guiding layer comprising active lasing material and formed on the first cladding layer, a second cladding layer formed on the core or guiding layer; an index-confined optical waveguide having a width, providing lateral optical confinement and extending longitudinally from a first end of the device to a second position between the first end and a second end of the device; an optically active region disposed in the core or guiding layer beneath and/or within the waveguide and extending longitudinally to a third position between the first end of the device and the second position, an electrical contact disposed above the waveguide and extending longitudinally to have an end at the third position; a first optically passive region of the core or guiding layer extending from the second position to the second end of the device, a width of the first optically passive region being broader than the width of the waveguide such that, in use, an optical output from the waveguide diffracts upon traversing the first optically passive region; and a second optically passive region within the core or guiding layer of the device longitudinally extending from the third position to the second position and having said width of the waveguide, the waveguide from the third position to the second position being contact-free.