Abstract: A keypad includes a light guide panel, the interior of which light propagates through, a film positioned on the upper surface of the light guide panel and having at least one key button positioned on the upper surface thereof, and at least one reflective pattern fixedly positioned with respect to the light guide panel to reflect a part of the light, which propagates through the interior of the light guide panel, towards the key button.

Abstract: A keypad includes a light guide panel, the interior of which light propagates through; at least one key button positioned on the upper surface of the light guide panel; and at least one reflective pattern fixedly positioned with respect to the light guide panel to reflect a part of the light, which propagates through the interior of the light guide panel, towards the key button.

Abstract: A zoom lens includes a first lens group having a negative refracting force, a second lens group having a positive refracting force and being aligned closer to an image surface than the first lens group, and a third lens group aligned closer to the image surface than the second lens group. The distance between first and second lens groups is shortened and the distance between second and third lens groups is lengthened as the zoom lens performs zooming action from a wide angle position to a telephoto position.

Abstract: A semiconductor monolithic integrated optical transmitter including a plurality of active layers formed on a semiconductor substrate is disclosed, which comprises: a distributed feedback laser diode including a grating for reflecting light with a predetermined wavelength and a first active layer for oscillating received light from the grating; an electro-absorption modulator including a second active layer for receiving light from the first active layer, wherein the received light intensity is modulated through a change of absorbency in accordance with an applied voltage; an optical amplifier including a third active layer for amplifying received light from the second active layer; a first optical attenuator between the first active layer and the second active layer; and a second optical attenuator between the second active layer and the third active layer.

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: A distributed feedback semiconductor laser and a method of manufacture includes first and second clad layers having predetermined refractive indexes that are formed on a semiconductor substrate. A guide layer propagates light between the first and second clad layers. An oscillating clad layer oscillates light at a predetermined wavelength and an amplifying clad layer amplifies the light with a predetermined gain between the first clad layer and the guide layer. The distributed feedback semiconductor laser is divided into a laser oscillation section including the oscillating clad layer and a laser amplification section including the amplifying active layer. First and second gratings are formed on the lower surface of the guide layer in the laser oscillation section and in the laser amplification section, respectively.

Abstract: A distributed feedback semiconductor laser and a method of manufacture includes first and second clad layers having predetermined refractive indexes that are formed on a semiconductor substrate. A guide layer propagates light between the first and second clad layers. An oscillating clad layer oscillates light at a predetermined wavelength and an amplifying clad layer amplifies the light with a predetermined gain between the first clad layer and the guide layer. The distributed feedback semiconductor laser is divided into a laser oscillation section including the oscillating clad layer and a laser amplification section including the amplifying active layer. First and second gratings are formed on the lower surface of the guide layer in the laser oscillation section and in the laser amplification section, respectively.

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: A 0.98 &mgr;m semiconductor laser of a ridge waveguide (RWG) structure includes: to be lengthen the durability of a semiconductor laser by increasing a catastrophic optical damage (COD) level, a ridge having a fixed width and length so that the strip may stop in the position of 30 &mgr;m on the basic of end portion of an output facet along length direction of a resonator; and a non-waveguide region in the end portion of both sides of a resonator.

Abstract: A 0.98 &mgr;m semiconductor laser of a ridge waveguide (RWG) structure includes: to be lengthen the durability of a semiconductor laser by increasing a catastrophic optical damage (COD) level, a ridge having a fixed width and length so that the strip may stop in the position of 30 &mgr;m on the basic of end portion of an output facet along length direction of a resonator; and a non-waveguide region in the end portion of both sides of a resonator.

Abstract: A 0.98 &mgr;m semiconductor laser of a ridge waveguide (RWG) structure includes: to be lengthen the durability of a semiconductor laser by increasing a catastrophic optical damage (COD) level, a ridge having a fixed width and length so that the strip may stop in the position of 30 &mgr;m on the basic of end portion of an output facet along length direction of a resonator; and a non-waveguide region in the end portion of both sides of a resonator.

Abstract: A method of fabricating a semiconductor laser comprises the steps of sequentially depositing a lower cladding layer, an active layer, a first upper cladding layer, an etching stop layer, a second upper cladding layer and an ohmic contact layer over a compound semiconductor substrate, forming an etching mask over the ohmic contact layer so as to expose channel regions and to shield the ridge regions between the channel regions, performing wet etching to etch the ohmic contact layer and the second upper cladding layer so as to expose the etching stop layer so as to form the channels and the ridges having narrower widths than the parts of the etching mask shielding the ridge regions, and implanting dopant ions into the parts of the first upper cladding layer and the active layer below the channels to form ion-implanted regions by using the etching mask as the ion implantation mask.

Abstract: The present invention relates to high power semiconductor laser device and method for fabricating the same utilizing ion implanting process, by which a beam steering phenomenon of an optical output due to filaments is eliminated. This elimination is achieved by a periodically varying gain given for a resonator of the semiconductor laser device. That is, this invention changes a gain distribution which causes the generation of filaments in the resonator into different distribution. According to the present invention, there is formed an insulation layer through ion implantation to an active layer to adjust current density implanted to the active layer, thereby eliminating non-uniform distribution of the light along the longitudinal direction of the resonator.

Abstract: Disclosed is a method for fabricating a planar buried heterostructure laser diode, comprising the steps of sequentially forming a first clad layer, an undoped active layer and a second clad layer on a substrate so as to complete a first crystal growth; forming a patterned mask layer on the second clad layer; non-selectively etching the second clad layer, the active layer, the first clad layer and the substrate using the mask layer as an etching mask; selectively etching the substrate and the first and second layers; sequentially forming a first and second current blocking layers on a structure formed by the selective etching step so as to complete a second crystal growth; sequentially forming a third clad layer and an ohmic contact layer thereon after removal of the mask layer so as to complete a third crystal growth; and forming a first electrode on a rear surface of the substrate and forming a second electrode on a surface of the third clad layer.

Abstract: A method for manufacturing the semiconductor laser device comprising the steps of sequentially forming an active layer, a photo-waveguide layer, a cladding layer, and an ohmic contact layer on an upper surface of an InP substrate; forming a first patterned dielectric layer on the ohmic contact layer; depositing a patterned photoresist on the ohmic contact layer to define a p- electrode stripe layer; forming the p- electrode stripe layer only on a part of the ohmic contact layer; performing an annealing process; etching back the layers until the photo-waveguide layer is exposed, using the first patterned dielectric layer and the p- electrode stripe layer as an etching mask, to form a ridge; depositing a second dielectric layer on the substrate formed thus; selectively removing the second dielectric layer to form a contact hole on the p- electrode stripe layer; coating a bonding pad metal layer on the second dielectric layer and in the contact hole; and coating an n- electrode metal layer on bottom surface of t