Abstract: The present invention relates to a semiconductor based parabolic waveguide-type collimating lens and a monolithically integrated type tunable external cavity laser diode light source.

Abstract: Provided is an apparatus and method for simultaneous optical wavelength conversion and optical clock signal extraction using semiconductor optical amplifiers (SOAs).

Abstract: The present invention relates to a semiconductor based parabolic waveguide-type collimating lens and a monolithically integrated type tunable external cavity laser diode light source.

Abstract: Provided is an optical semiconductor device including: an active layer having at least one quantum well layer and at least one barrier layer; a clad layer formed adjacent to the active layer; and a tunneling barrier layer formed between the active layer and the clad layer to be connected to the quantum well layer and formed of a material having a band-gap energy larger than the barrier layer, whereby it is possible to improve the drive characteristics at a high temperature and a high drive current by increasing a confinement effect of carriers such as electrons and holes in the active layer.

Abstract: Provided is a waveguide photodetector including: a first clad layer disposed on a substrate; a core layer disposed on the first clad layer and for absorbing predetermined light; a second clad layer disposed on the core layer; and at least one subsidiary layer inserted in the first clad layer and the second clad layer. In this structure, the photodetector has about the same spot size as that of an optical fiber or planar lightwave circuit (PLC), so that incident light can be absorbed without loss, and the photodetector can more efficiently combine with the optical fiber or PLC and operate even at high power.

Abstract: Provided is a method of fabricating a ridge type waveguide integrated semiconductor optical device.

Abstract: Provided is a method for manufacturing a planar buried semiconductor optical amplifier in which a spot size converter with a double-core structure is integrated, comprising the steps of: after growing a lower cladding layer, a lower waveguide layer and an upper cladding layer on a substrate, patterning a portion of thickness of the lower cladding layer, the lower waveguide layer and the upper cladding layer through an etching process using a dielectric layer pattern to form a lower waveguide; growing a planarization layer on the etched portions of the lower cladding layer, the lower waveguide layer and the upper cladding layer to smooth a surface; after removing the dielectric layer pattern, growing a space layer, an upper waveguide layer and a first cladding layer on the overall upper surface; patterning the first cladding layer, the upper waveguide layer and the space layer through the etching process using the dielectric layer pattern to form an upper waveguide having a horizontal taper area; after growing