Abstract: A multi-channel optical receiving module includes a first substrate disposed on a bench, optical fibers disposed in grooves of the first substrate, a first lens disposed on the first substrate and collimating optical signals through the optical fibers, a second substrate disposed on the bench at a side of the first substrate, a light receiving device disposed on the second substrate, a second lens disposed over the light receiving device, a mirror reflecting the optical signals between the first lens and the second lens, and a block fixing the mirror. The block includes through-holes transmitting the optical signals between the first and second lenses without refraction of the optical signals.

Abstract: Provided is a wavelength division multiplexing (WDM) optical transmitting apparatus including first to n-th optical transmitters configured to output first to n-th optical signals having different wavelengths, respectively; a wavelength multiplexer configured to multiplex the first to n-th optical signals and generate an output optical signal; a tap coupler configured to receive the output optical signal and generate a controlling optical signal based on some of the output optical signal; a controlling photodetector configured to receive the controlling optical signal and output an optical current based on the controlling optical signal; and a controller configured to control each of the first to n-th optical transmitters based on the optical current, wherein the controller comprises a look-up table, sequentially detects driving conditions for the first to n-th optical transmitters, stores the detected driving conditions in the look-up table, and controls the first to n-th optical transmitters based on the de

Abstract: A semiconductor optical device includes a first mode converting core, a light amplification core, a second mode converting core, and a light modulation core disposed in a first mode converting region, a light amplification region, a second mode converting region, and a light modulating region of a semiconductor substrate, respectively, and a current blocking section covering at least sidewalls and a top surface of the light amplification core. The first mode converting core, the light amplification core, the second mode converting core, and the light modulation core are arranged along one direction in the order named, and are connected to each other in butt joints. The current blocking section includes first, second, and third cladding patterns sequentially stacked. The second cladding pattern is doped with dopants of a first conductivity type, and the first and third cladding patterns are doped with dopants of a second conductivity type.

Abstract: Disclosed are an optical waveguide platform with integrated active transmission device and monitoring photodiode. The optical waveguide platform with hybrid integrated optical transmission device and optical active device includes an optical waveguide region formed by stacking a lower cladding layer, a core layer and an upper cladding layer on a substrate; a trench region formed by etching a portion of the optical waveguide region; and a spot expanding region formed on the core layer in the optical waveguide region, in which the optical transmission device is mounted in the trench region and the optical active device is flip-chip bonded to the spot expanding region. The monitoring photodiode is flip-chip bonded to the spot expanding region of the core layer of the optical waveguide, thereby monitoring output light including an optical coupling loss that occurs during flip-chip bonding.

Abstract: A semiconductor optical device includes a first mode converting core, a light amplification core, a second mode converting core, and a light modulation core disposed in a first mode converting region, a light amplification region, a second mode converting region, and a light modulating region of a semiconductor substrate, respectively, and a current blocking section covering at least sidewalls and a top surface of the light amplification core. The first mode converting core, the light amplification core, the second mode converting core, and the light modulation core are arranged along one direction in the order named, and are connected to each other in butt joints. The current blocking section includes first, second, and third cladding patterns sequentially stacked. The second cladding pattern is doped with dopants of a first conductivity type, and the first and third cladding patterns are doped with dopants of a second conductivity type.

Abstract: Disclosed is a light generating device which comprises a first reflective semiconductor optical amplifier emitting a first light along a first direction, a second reflective semiconductor optical amplifier emitting the second light in a direction opposite to the first direction, an optical distributer reflecting a part of an incident light and to pass the remaining of the incident light, and an optical comb filter passing a wavelength component of a specific period.

Abstract: A wavelength-tunable external cavity laser generating device is provided. The wavelength-tunable external cavity laser generating device includes a reflection-type multi-mode interferometer, an optical amplifier disposed between the reflection-type multi-mode interferometer and an external wavelength-tunable reflector to amplify light, and an optical signal processor configured to process light from the reflection-type multi-mode interferometer. The reflection-type multi-mode interferometer includes a multi-mode waveguide, an input waveguide connecting the optical amplifier and one end of the multi-mode waveguide, and an output waveguide configured to connect the optical signal processor and the other end of the multi-mode waveguide.

Abstract: The present invention relates to a spot size converter and a method of fabricating the same, which provides efficient coupling between an optical fiber and integrated devices of optical waveguide. The spot size converter has an input and output optical waveguides formed in a vertical double-layer structure. Integrated to the output optical waveguide, an unidirectional side-tapered optical waveguide is formed. Due to the tapered structure of the optical waveguide, the effective refective index gradually changes along the length of the waveguide. Thus, the spot size of the optical signal gradually changes while the optical signal travels within the tapered optical waveguide. Therefore, the present invention effectively eliminates or minimizes the coupling loss and the reflection loss between the optical fiber and the devices connected to the spot size converter.

Abstract: The present invention relates to a spot size converter and a method of fabricating the same, which provides efficient coupling between an optical fiber and integrated devices of optical waveguide. The spot size converter has an input and output optical waveguides formed in a vertical double-layer structure. Integrated to the output optical waveguide, an unidirectional side-tapered optical waveguide is formed. Due to the tapered structure of the optical waveguide, the effective refective index gradually changes along the length of the waveguide. Thus, the spot size of the optical signal gradually changes while the optical signal travels within the tapered optical waveguide. Therefore, the present invention effectively eliminates or minimizes the coupling loss and the reflection loss between the optical fiber and the devices connected to the spot size converter.

Abstract: A structure of optical grating slab waveguide including a light waveguiding layer with linear refractive index disposed on another waveguiding layer having a nonlinear refractive index. The refractive index of nonlinear waveguiding material is a function of intensity of optical power incident therein. The structure of this invention provides an optical waveguide having improved optically coupling coefficient. A optical grating structures formed with a slab waveguide of this invention may be used as a wavelength selective coupling device of bidirectional optical coupler that is particularly useful as demultiplexer or multiplexer.

Abstract: The present invention provides to a novel grating-assisted directional coupler which is capable of appending a nonlinear thin film to a conventional linear grating-assisted directional coupler, to thereby significantly improve coupling efficiency and hence design a structure having optical multistable characteristics, which comprises; a thin film nonlinear optical waveguide with third-order nonlinearity, which having a first thickness; a first linear optical waveguide formed on the thin film nonlinear optical waveguide, which having a second thickness, wherein a linear refractive index of the first linear optical waveguide is more than that of the thin film nonlinear optical waveguide; an optical waveguide grating patterned in equi-distanced on top surface of the nonlinear optical waveguide; and a second optical waveguide formed at a portion which is displaced from top surface of the first linear optical waveguide by a predetermined distance.

Abstract: A structure for a nonlinear grating coupler which is capable of providing a structure that a tapered nonlinear thin film and a linear waveguide grating structure are combined and a nonlinear grating coupler that a stepped nonlinear thin film and a linear optical waveguide grating structure are combined. The structure includes a tapered nonlinear thin film having a third-order nonlinearity, a linear optical waveguide having a refractive index greater than a linear refractive index of a nonlinear thin film formed on the tapered nonlinear thin film, and a grating structure formed on the linear optical waveguide.

Abstract: A nonlinear Y-junction waveguide structure includes a straight linear waveguide, and a nonlinear waveguide partially joined to the linear waveguide and bent through a desired angle at an output end portion thereof, whereby incident light coming into the linear waveguide travels mainly along the linear waveguide when it has a power lower than a predetermined level while traveling mainly along the nonlinear waveguide when it has a power not lower than the predetermined level. The nonlinear Y-junction waveguide structure has an increased branching angle as compared to the conventional completely-operating optical device and exhibits an abrupt switching phenomenon. Accordingly, it is possible to achieve an easy adjustment of the critical power. In this regard, there is no difficulty in the fabrication of the waveguide structure.

Abstract: A wavelength division demultiplexing device, and a system using the device are disclosed, in which there is utilized a Pabry-Perot etalon using as a spacer layer a Kerr medium in which the refractive index is varied in accordance with the intensity of beams.