Abstract: An image scanning apparatus for realizing an image on a screen includes: a spatial light modulator module for diffracting light beams having different wavelengths into relevant modes; and an iris for limiting light beams of modes except a mode of 0th-order among the modes diffracted by the spatial light modulator module.

Abstract: Disclosed is a method for maintaining wavelength-locking of a Fabry-Perot laser regardless of a change of external temperature even though a temperature controller is not used, and a wavelength division multiplexing (WDM) light source using the method, as an economical light source used in a WDM optical communication field. The WDM light source comprises a Fabry-Perot laser for injecting spectrum-spliced incoherent light to amplify and output only an oscillation mode matching with a wavelength of the injected light, and a bias controlling unit for adjusting a bias current supplied to the Fabry-Perot laser to a value adjacent to a threshold current of the Fabry-Perot laser, whose threshold current is changed according to a temperature and a relationship between the injected light changed depending to a temperature and a wavelength of the oscillation mode.

Abstract: An optically pumped semiconductor laser and an optical pumping method are disclosed. The optically pumped semiconductor laser includes an output mirror and a reflective mirror for forming a resonant region therebetween, a gain medium disposed between the output mirror and the reflective mirror and a light source for applying a source light in a direction between the output mirror and the gain medium to activate the gain medium, whereby the optical axes of the light from the source light and the light generated from the gain medium are substantially perpendicular to each other and the optical axes of a second harmonic generated from a nonlinear crystal is substantially equal to the optical axis of the light generated from the gain medium.

Abstract: A method of growing a semiconductor layer in a selective area by Metal Organic Chemical Vapor Deposition (MOCVD) and a mask pattern for s ame, includes a first mask pattern and a second mask pattern that are formed on a semiconductor substrate having a (100) crystalline plane. The first mask pattern has a first window wider than the selective area and a second mask pattern has a second window and a third window. The second window is defined by spacing the second mask pattern from the first mask pattern, in correspondence with a blocking area for blocking the surface migration of III-group semiconductor source gases at edges of the first window. The third window is as wide as the selective area. The semiconductor layer is grown by MOCVD on the semiconductor substrate exposed by the second and third windows. Trenches can be etched in the second and third windows and growth layers extend from the trench beyond the surface of the InP to block gas dispersion.

Abstract: An optical transmitter module for creating an optical signal having the same wavelength as an incoherent light inputted thereinto is provided. The module includes a substrate, a multi-layer crystal growth layer including a first area for amplifying the incoherent light and the optical signal and a second area for creating an optical signal having the same wavelength as the incoherent light amplified by means of the first area, and an electrode unit for independently injecting currents into the areas of the multi-layer crystal growth layer. A light generated at a broadband light source is spectrum-sliced and injected into the optical transmitter module so that a wavelength division multiplexing light source is realised.

Abstract: A distributed feedback semiconductor laser oscillating in a single mode and a method for manufacturing the same is disclosed. The distributed feedback semiconductor laser includes an active layer; a clad layer formed adjacent to the active layer; and diffraction gratings periodically formed in the clad layer and separated from each other by a predetermined distance. The diffraction gratings are formed of a nonconductor so that a current injected into the active layer is partially blocked and distribution of gain coefficient is varied. The nonconductor is an oxidized semiconductor material.

Abstract: A method of detecting an etching end-point includes the steps of: forming a mask on a pattern area of an etching object; forming an etching indicator on an etching area of the etching object, which is not covered by the mask; etching the etching object using the mask; and evaluating the size of a remaining object covered by the mask using the etching indicator.

Abstract: A semiconductor optical device including an SSC region includes a semiconductor substrate, a lower clad layer grown on the semiconductor substrate, and an upper clad layer grown on the lower clad layer. The semiconductor optical device with an SSC (Spot Size Conversion) area includes a gain area including an active layer grown between the lower clad layer and the upper clad layer to generate/amplify an optical signal; and an SSC (Spot Size Conversion) area including a waveguide layer extended from the active layer positioned between the lower and upper clad layers, such that it performs a spot size conversion (SSC) process of the optical signal generated from the gain area and generates the SSC-processed optical signal.

Abstract: A method of growing a semiconductor layer in a selective area by Metal Organic Chemical Vapor Deposition (MOCVD) and a mask pattern for s ame, includes a first mask pattern and a second mask pattern that are formed on a semiconductor substrate having a (100) crystalline plane. The first mask pattern has a first window wider than the selective area and a second mask pattern has a second window and a third window. The second window is defined by spacing the second mask pattern from the first mask pattern, in correspondence with a blocking area for blocking the surface migration of III-group semiconductor source gases at edges of the first window. The third window is as wide as the selective area. The semiconductor layer is grown by MOCVD on the semiconductor substrate exposed by the second and third windows. Trenches can be etched in the second and third windows and growth layers extend from the trench beyond the surface of the InP to block gas dispersion.

Abstract: An optical transmitter module for creating an optical signal having the same wavelength as an incoherent light inputted thereinto is provided. The module includes a substrate, a multi-layer crystal growth layer including a first area for amplifying the incoherent light and the optical signal and a second area for creating an optical signal having the same wavelength as the incoherent light amplified by means of the first area, and an electrode unit for independently injecting currents into the areas of the multi-layer crystal growth layer. A light generated at a broadband light source is spectrum-sliced and injected into the optical transmitter module so that a wavelength division multiplexing light source is realised.

Abstract: A WDM optical transmitter using a wideband gain laser comprises a plurality of wideband gain lasers and a wavelength division multiplexer. Each wideband gain laser includes a gain medium with a 3 dB bandwidth of 40 nm or more at a threshold current, and it amplifies corresponding incoherent light injected into the gain medium and outputs a corresponding channel. The multiplexer multiplexes channels, outputted from the wideband gain lasers, into an optical signal in a WDM scheme and outputs the multiplexed optical signal.

Abstract: A WDM (Wavelength Division Multiplexing) optical transmitter using a Fabry-Perot laser is disclosed.

Abstract: Disclosed is a photodiode with improved light-receiving efficiency and coupling effect with an optical fiber, whose capacitance may be decreased. The inventive photodiode includes a substrate; a buffer layer and a light-absorbing layer laminated in sequence on the substrate; an epitaxial layer formed on the upper surface of the light absorbing layer and having an active region with a surface in a convex lens shape so that it has greater surface area and more effective light-receiving area than an active region defined in a two-dimensional plane, the active region further having a convex surface can harvest light with its convex-lens characteristics; a dielectric layer formed on the upper surface of the epitaxial layer; a first metal electrode formed on an upper surface of the dielectric layer; and, a second metal electrode formed on an under surface of the substrate.

Abstract: Disclosed is a method for maintaining wavelength-locking of a Fabry-Perot laser regardless of a change of external temperature even though a temperature controller is not used, and a wavelength division multiplexing (WDM) light source using the method, as an economical light source used in a WDM optical communication field. The WDM light source comprises a Fabry-Perot laser for injecting spectrum-spliced incoherent light to amplify and output only an oscillation mode matching with a wavelength of the injected light, and a bias controlling unit for adjusting a bias current supplied to the Fabry-Perot laser to a value adjacent to a threshold current of the Fabry-Perot laser, whose threshold current is changed according to a temperature and a relationship between the injected light changed depending to a temperature and a wavelength of the oscillation mode.

Abstract: A wavelength-locked, integrated optical signal source structure using a semiconductor laser device is disclosed. The optical source structure has a semiconductor laser formed on a semiconductor substrate, and an etched portion coupled with an output end of the semiconductor laser. The etched portion is configured to pass on a first amount of light beam radiated by the semiconductor laser, and to reflect a second amount of light beam by a given reflection angle. A multiple microcavity is formed in a position spaced apart from the etched portion, and the first amount of light beam is incident upon the multiple microcavity. The optical source structure has a first optical detector for detecting the first amount of light beam passing through the multiple microcavity, and a second optical detector for detecting the second amount of light beam reflected by a slanted, reflecting surface portion of the etched portion.

Abstract: Disclosed is a photodiode with improved light-receiving efficiency and coupling effect with an optical fiber, whose capacitance may be decreased. The inventive photodiode includes a substrate; a buffer layer and a light-absorbing layer laminated in sequence on the substrate; an epitaxial layer formed on the upper surface of the light absorbing layer and having an active region with a surface in a convex lens shape so that it has greater surface area and more effective light-receiving area than an active region defined in a two-dimensional plane, the active region further having a convex surface can harvest light with its convex-lens characteristics; a dielectric layer formed on the upper surface of the epitaxial layer; a first metal electrode formed on an upper surface of the dielectric layer; and, a second metal electrode formed on an under surface of the substrate.

Abstract: Disclosed is a photodiode with improved light-receiving efficiency and coupling effect with an optical fiber, whose capacitance may be decreased. The inventive photodiode includes a substrate; a buffer layer and a light-absorbing layer laminated in sequence on the substrate; an epitaxial layer formed on the upper surface of the light absorbing layer and having an active region with a surface in a convex lens shape so that it has greater surface area and more effective light-receiving area than an active region defined in a two-dimensional plane, the active region further having a convex surface can harvest light with its convex-lens characteristics; a dielectric layer formed on the upper surface of the epitaxial layer; a first metal electrode formed on an upper surface of the dielectric layer; and, a second metal electrode formed on an under surface of the substrate.

Abstract: The invention relates to the fields of molecular biology, bacteriology and industrial fermentation. More specifically, the invention relates to the identification and isolation of nucleic acid sequences and proteins of sorbitol dehydrogenases and cytochrome c of the strains, Ketogulonigenium spp. The invention further relates to the fermentative production of L-sorbose from D-sorbitol and the subsequent production of 2-keto-L-gulonic acid.

Abstract: Disclosed is a photodiode with improved light-receiving efficiency and coupling effect with an optical fiber, whose capacitance may be decreased. The inventive photodiode includes a substrate; a buffer layer and a light-absorbing layer laminated in sequence on the substrate; an epitaxial layer formed on the upper surface of the light absorbing layer and having an active region with a surface in a convex lens shape so that it has greater surface area and more effective light-receiving area than an active region defined in a two-dimensional plane, the active region further having a convex surface can harvest light with its convex-lens characteristics; a dielectric layer formed on the upper surface of the epitaxial layer; a first metal electrode formed on an upper surface of the dielectric layer; and, a second metal electrode formed on an under surface of the substrate.

Abstract: A wavelength-locked, integrated optical signal source structure using a semiconductor laser device is disclosed. The optical source structure has a semiconductor laser formed on a semiconductor substrate, and an etched portion coupled with an output end of the semiconductor laser. The etched portion is configured to pass on a first amount of light beam radiated by the semiconductor laser, and to reflect a second amount of light beam by a given reflection angle. A multiple microcavity is formed in a position spaced apart from the etched portion, and the first amount of light beam is incident upon the multiple microcavity. The optical source structure has a first optical detector for detecting the first amount of light beam passing through the multiple microcavity, and a second optical detector for detecting the second amount of light beam reflected by a slanted, reflecting surface portion of the etched portion.