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71. 发明专利

JPH06209482A PICTURE REPRODUCTION DEVICE 失效
公开(公告)号：JPH06209482A
公开(公告)日：1994-07-26
申请号：JP241393
申请日：1993-01-11
申请人： NIPPON TELEGRAPH & TELEPHONE
发明人： SAKAI YOSHIHISA , ISHIBASHI SHIGEO
IPC分类号： G02F1/33 , H04N7/22 , H04N9/14
摘要： PURPOSE:To obtain the picture reproduction device by which a high definition picture is reproduced at a very fast speed by converting an optical signal into a picture signal directly visible. CONSTITUTION:The device is provided with an optical fiber 101 for picture optical signal transmission, a wavelength conversion section 102 applying wavelength conversion to the picture optical signal into a visual light signal, and a sweep section 103 scanning (sweeping) the visual light signal subject to wavelength conversion and displaying a visual picture onto a screen 104 or the like. The wavelength conversion section 102 receives an input signal light and outputs a visual light at a specific wavelength of the input signal light and the sweep section 103 displays the picture on the screen 104 by scanning the visual light in 2-dimension in left/right/upper/lower directions in matching the timing of the signal light. A crystal or an amorphous material formed by doping rare-earth ions is used for the wavelength conversion section 102.

72. 发明专利

JPH06123901A LIGHT FREQUENCY CONVERSION DEVICE 失效
公开(公告)号：JPH06123901A
公开(公告)日：1994-05-06
申请号：JP27453992
申请日：1992-10-13
申请人： NIPPON TELEGRAPH & TELEPHONE
发明人： ITO HIROKI , YUBE MASAO , SAKAI YOSHIHISA
IPC分类号： G02F1/35
摘要： PURPOSE:To provide the light frequency conversion device capable of making light frequency conversion of a wide band at a high speed. CONSTITUTION:Control light 44 of a light frequency f3 generated from a control light source 32 is multiplexed via a half mirror 35 with signal light 43 of a light frequency f1 and these control light rays are made incident on a nonlinear optical medium having an optical Kerr effect and a negative group speed dispersion characteristic, i.e., silica optical fiber 31 in this embodiment, thereby, modulation unstability is induced in the optical fiber 31 to generate the modulated waves repeating at the differential frequency ¦f1-f3¦ between both light waves. The side band components of the frequencies 2f3-f1 and 2f1-f3 of the modulated waves are taken out by an optical wavelength filter 42. Output light 45 which has the information of the signal light 43 and is frequency converted from the frequency f1 is thereby obtd.

73. 发明专利

JPH05303121A 失效
公开(公告)号：JPH05303121A
公开(公告)日：1993-11-16
申请号：JP10755392
申请日：1992-04-27
申请人： NIPPON TELEGRAPH & TELEPHONE
发明人： ITO HIROKI , ISHIBASHI SHIGEO , YOKOO ATSUSHI , SAKAI YOSHIHISA
IPC分类号： G02F1/35 , H01S3/06 , H01S3/10 , H01S3/108
摘要： PURPOSE:To obtain the nonlinear optical device which can process a time-series optical signal and effectively utilize the output of an external light source. CONSTITUTION:The light from an exciting light source 28 is made incident on an optical resonator 24 and light is emitted by a nonlinear optical medium 24c in the optical resonator 24 which has optical nonlinear effect and a laser gain, and circulated and amplified by reflecting mirrors 24a and 24b and a saturable absorber 24d in a mode locked state to generate control light pulses 30; and a sum frequency component generated between the control light pulses 30 and signal light pulses 29 which are made incident on the nonlinear optical medium 24c of the optical resonator 24 is extracted by a wavelength filter 27.

74. 发明专利

JPH05291677A 失效
公开(公告)号：JPH05291677A
公开(公告)日：1993-11-05
申请号：JP11856392
申请日：1992-04-13
申请人： NIPPON TELEGRAPH & TELEPHONE
发明人： SAKAI YOSHIHISA , KITAGAWA TAKESHI , SUDO SHOICHI , HORIGUCHI MASAHARU
IPC分类号： H01S5/068 , H01S3/133
摘要： PURPOSE:To obtain a laser output stably over a wide frequency range by detecting a light of a frequency deviated from a reference frequency passed through an absorption medium for absorbing a light having the reference frequency as an error signal, and feeding back the error signal. CONSTITUTION:An emitted light of a main laser 12 oscillated by exciting by an exciting light emitted from an exciting semiconductor laser 11 is modulated by an optical frequency modulator 16 to become a parallel beam light by a SELFOC lens 18, transmitted through an absorption cell 19, and photoelectrically converted by a photoreceiver 110. The laser 12 is wavelength-synchronized with an absorption line of carbon isotope element-substituted acetylene gas. A deviation of the laser 12 modulated by the modulator 16 from the absorption line of the acetylene gas of the line of a wavelength reference is detected by a lock-in amplifier 111 by a signal from the photoreceiver 110, and the detected error signal is fed back to more stabilize the output of the laser 12.

75. 发明专利

JPH04307822A WAVELENGTH MULTIPLEX OPTICAL COMMUNICATION EQUIPMENT 失效
公开(公告)号：JPH04307822A
公开(公告)日：1992-10-30
申请号：JP7283391
申请日：1991-04-05
申请人： NIPPON TELEGRAPH & TELEPHONE
发明人： SAKAI YOSHIHISA , KUROKAWA TAKASHI , HIRABAYASHI KATSUHIKO , TSUDA HIROYUKI
IPC分类号： G02F1/13 , H04J14/00 , H04J14/02
摘要： PURPOSE:To select and demodulate plural optical signals whose wavelength differs from each other with high accuracy. CONSTITUTION:A sender side is provided with plural wavelength stabilizing lasers 6 whose oscillating wavelength is made stable and different while using a medium 12 absorbing only a light with a prescribed wavelength as a wavelength reference, plural optical modulators 2 applying a signal to a laser beam from each laser 6 and an optical coupler 3 overlapping each laser beam after optical modulation and the result is sent through an optical fiber. A receiver side is provided with a variable wavelength filter 7 using a liquid crystal and selecting optically a wavelength of each laser beam sent through the optical fiber to select the beam with high accuracy and with a light receiving device 5 which applies photoelectric conversion to the laser beam and demodulates it.

76. 发明专利

JPH04118533A OPTICAL FREQUENCY COUNTER 失效
公开(公告)号：JPH04118533A
公开(公告)日：1992-04-20
申请号：JP23958290
申请日：1990-09-10
申请人： NIPPON TELEGRAPH & TELEPHONE
发明人： SAKAI YOSHIHISA , SUDO SHOICHI
IPC分类号： G01J9/00
摘要： PURPOSE:To highly precisely identify an optical frequency by determining the beat signal between a plurality of oscillating frequency stabilized light sources having a medium absorbing a light of a determined wavelength as a frequency standard, and a light to be measured. CONSTITUTION:A light to be measured 110 is divided into two by an optical coupler 13, and emitted to optical couplers 14, 15 respectively. These lights are combined with oscillating frequency stabilized light sources 11, 12 therein, and photoelectrically converted in light receivers 16, 17. The beat signal is processed in an optical frequency judging circuit 18 to identify the optical frequency of the light to be measured, which is displayed on a light frequency display part 19. Thus, by finding out the beat signal with a plurality of oscillating frequency stabilized light sources using a medium absorbing a light of a determined wavelength as a frequency standard, the absolute frequency of the measured light can be highly precisely identified, and the oscillating frequency of a laser beam can be highly precisely measured.

77. 发明专利

JPH0473790A ENCIPHERING METHOD AND ENCIPHERING DEVICE 失效
公开(公告)号：JPH0473790A
公开(公告)日：1992-03-09
申请号：JP18685090
申请日：1990-07-13
申请人： NIPPON TELEGRAPH & TELEPHONE
发明人： SAKAI YOSHIHISA , KUROKAWA TAKASHI , FUKUSHIMA SEIJI
IPC分类号： G09C1/00 , G09C1/02 , H04L9/06 , H04L9/18 , H04N1/44
摘要： PURPOSE:To execute the encipherment and decoding of data of a large capacity at a high speed by executing an operation of key array data determined in advance and exclusive OR to original array data. CONSTITUTION:When original array data is inputted to one piece of two pieces of liquid crystal panels 211, 212, and key array data is inputted to the other one piece, as for its output, as to only the part in which the key array data is '1', the original array data is inverted and cipher array data is obtained. Also, at the time of decoding, when the cipher array data is inputted to one piece of two pieces of liquid crystal panels 211, 212, and the key array data is inputted to the other one piece, as for its output, as to only the part in which the key array data is '1', the cipher array data is inverted, and the original array data can be reproduced. In this case, in the case erroneous key array data is inputted, it becomes array data being different from the original array data. Since the processing for enciphering an image is executed simultaneously with regard to all picture elements by an optical operation, the encipherment can be executed at a high speed with respect to an image of high definition having a large information quantity.

78. 发明专利

JPH03208386A LASER SYSTEM 失效
公开(公告)号：JPH03208386A
公开(公告)日：1991-09-11
申请号：JP243190
申请日：1990-01-11
申请人： NIPPON TELEGRAPH & TELEPHONE
发明人： SAKAI YOSHIHISA , KUROKAWA TAKASHI , FUKUSHIMA SEIJI
IPC分类号： G02B6/42 , H01S3/101
摘要： PURPOSE:To make it possible to obtain parallel rays, whose intensity can be modulated and have an even intensity distribution, by a method wherein the intensity of a laser beam from a laser is varied and intensity modulated light is spatially converted into the parallel rays. CONSTITUTION:A beam emitted from a laser module 11 capable of leading out a laser beam via an optical fiber 14 is linked to an acoustooptic modulator 12. An optical system for leading out the laser beam through the fiber 14 is mounted integrally on a laser along with the fiber 14. An optical fiber input/ output type is used as the modulator 12, the primary diffracted output of the modulator 12 is incided on a collimator lens 13 through an optical fiber 15 and converted into parallel rays 17 of an arbitrary intensity by the lens 3 constituted by combining two sheets or more of lenses with each other. Thereby, large-aperture parallel laser rays having a high spatial evenness can be obtained.

79. 发明专利

JPH0374891A SEMICONDUCTOR LIGHT EMITTING ELEMENT 失效
公开(公告)号：JPH0374891A
公开(公告)日：1991-03-29
申请号：JP21157889
申请日：1989-08-17
申请人： NIPPON TELEGRAPH & TELEPHONE
发明人： KAWAMURA YUICHI , SAKAI YOSHIHISA , ASAI HIROMITSU , NAGANUMA MITSURU
IPC分类号： H01L33/06 , H01L33/30 , H01L33/40 , H01S5/00 , H01S5/042
摘要： PURPOSE:To enable easy matching of lattice and variable refraction factor in a wide range when an average lattice constant is equal to a substrate by forming second and fourth semiconductor layers by a supperlattice layer of three component mixed crystal semiconductor or four component mixed crystal semiconductor. CONSTITUTION:A semiconductor light emitting element has second and fourth semiconductor layers which are composed of a superlattice layer of three compo nent mixed crystal semiconductor or four component mixed crystal semiconduc tor. Otherwise, it is a semiconductor light emitting element where InGaAs is used as a three component mixed crystal semiconductor and second and fourth layers thereof are formed by a super lattice of In1-x, GaxAs/In1-yGayAs (0

80. 发明专利

JPH02292885A OSCILLATION WAVELENGTH STABILIZED SEMICONDUCTOR LASER DEVICE 失效
公开(公告)号：JPH02292885A
公开(公告)日：1990-12-04
申请号：JP11267889
申请日：1989-05-01
申请人： NIPPON TELEGRAPH & TELEPHONE
发明人： SUDO SHOICHI , SAKAI YOSHIHISA , YASAKA HIROSHI , IKEGAMI TETSUHIKO
IPC分类号： H01S3/137 , H01S5/00
摘要： PURPOSE:To realize a light absorption line narrow in width so as to make an oscillation frequency small in fluctuation with time by a method wherein gas including a mixed gas of light absorbing gas high in light absorbing property in a specific range of wavelength and inert gas is filled in a light absorbing gas cell at a normal pressure. CONSTITUTION:Gas containing a mixed gas obtained by mixing one or more kinds of light absorbing gases selected from such as C2H4, NH3 CO2, CH4, and the like which are possessed of a high light absorbing property in a wavelength range of 0.3-3.0mum with one or more kinds of inert gases selected from such as He, Ar, Ne, Xe, and the like is filled into a light absorbing gas cell 12 at a normal pressure. A control circuit 14 controls a current injected into a semiconductor laser so as to make the incident light volume of a photodetector from the light absorbing gas cell 12 minimum. As mentioned above, the partial pressure of light absorbing gas possessed of an intense light absorbing property in a wavelength range of 0.3-3.0mum is regulated by diluting it with inner gas of small molecular weight, whereby a light absorbing line of narrow width equivalent to that obtained under a depressurized condition can be realized and the fluctuation with time of an oscillation frequency can be made small.

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