公开(公告)号：DE69019498T2

公开(公告)日：1996-02-29

申请号：DE69019498

申请日：1990-12-27

Applicant: NEC CORP

Inventor： AJISAWA AKIRA ,  TERAKADO TOMOJI ,  YAMAGUCHI MASAYUKI ,  KOMATSU KEIRO

IPC: G02F1/015 ,  G02F1/025 ,  H01L31/0224 ,  H01L31/105 ,  H01S5/026 ,  H01S5/042

Abstract: An optical semiconductor device comprises a stripe-mesa structure provided on a semi-insulating substrate. The stripe-mesa structure comprises an undoped light absorption layer sandwiched by cladding layers, and burying layers on the both sides. For this structure, a device capacitance is decreased to provide wide bandwidth and ultra-high speed operation properties. This device is applied to an optical modulator, an integrated type optical modulator, and an optical detector.

公开(公告)号：CA1257924A

公开(公告)日：1989-07-25

申请号：CA481666

申请日：1985-05-16

Applicant: NEC CORP

Inventor： FUJIWARA MASAHIKO ,  AJISAWA AKIRA ,  SUZUKI SHUJI

IPC: H03K17/785 ,  H04Q3/52 ,  G02B6/10

Abstract: of the disclosure An optical switch circuit is configured as a matrix array to arbitrarily switch the connections between optical transmission channels. The optical switch circuit comprises a plurality of optical splitter coupled to input transmission channels, a plurality of optical switches arranged on the matrix crosspoints, each switch comprising an optoelectronic element and a light modulating element functioning as an electrooptic element, and a plurality of optical combiners coupled to output transmission channels. Thus, a small-sized optical switch circuit suitable for integration is realized. With this circuit, small crosstalk and high speed switching without distortion of broadband signals are expected. Further, this circuit provides a wide adaptability such that light transmitted through multi-mode optical fiber can be switched.

公开(公告)号：DE3587515T2

公开(公告)日：1994-03-17

申请号：DE3587515

申请日：1985-05-15

Applicant: NEC CORP

Inventor： FUJIWARA MASAHIKO ,  AJISAWA AKIRA ,  SUZUKI SHUJI

IPC: H03K17/785 ,  H04Q3/52 ,  H04B10/12

Abstract: An optical switch circuit is configured as a matrix array to arbitrarily switch the connections between optical transmission channels. The optical switch circuit comprises a plurality of optical splitter coupled to input transmission channels, a plurality of optical switches arranged on the matrix crosspoitns, each switch comprising an optoelectronic element and a light modulating element functioning as an electrooptic element, and a plurality of optical combiners coupled to output transmission channels. Thus, a small-sized optical switch circuit suitable for integration is realized. With this circuit, small crosstalk and high speed switching without distortion of broadband signals are expected. Further, this circuit provides a wide adaptability such that light transmitted through multi-mode optical fiber can be switched.

公开(公告)号：DE69019498D1

公开(公告)日：1995-06-22

申请号：DE69019498

申请日：1990-12-27

Applicant: NEC CORP

Inventor： AJISAWA AKIRA ,  TERAKADO TOMOJI ,  YAMAGUCHI MASAYUKI ,  KOMATSU KEIRO

IPC: G02F1/015 ,  G02F1/025 ,  H01L31/0224 ,  H01L31/105 ,  H01S5/026 ,  H01S5/042

Abstract: An optical semiconductor device comprises a stripe-mesa structure provided on a semi-insulating substrate. The stripe-mesa structure comprises an undoped light absorption layer sandwiched by cladding layers, and burying layers on the both sides. For this structure, a device capacitance is decreased to provide wide bandwidth and ultra-high speed operation properties. This device is applied to an optical modulator, an integrated type optical modulator, and an optical detector.

公开(公告)号：CA2033246C

公开(公告)日：1995-05-30

申请号：CA2033246

申请日：1990-12-27

Applicant: NEC CORP

Inventor： AJISAWA AKIRA ,  TERAKADO TOMOJI ,  YAMAGUCHI MASAYUKI ,  KOMATSU KEIRO

IPC: G02B6/12 ,  G02B6/13 ,  G02F1/015 ,  G02F1/025 ,  H01S5/00 ,  H01S5/026 ,  H01S5/042

Abstract: An optical semiconductor device comprises a stripe-mesa structure provided on a semi-insulating substrate. The stripe-mesa structure comprises an undoped light absorption layer sandwiched by cladding layers, and burying layers on the both sides. For this structure, a device capacitance is decreased to provide wide bandwidth and ultra-high speed operation properties. This device is applied to an optical modulator, an integrated type optical modulator, and an optical detector.

公开(公告)号：DE3587515D1

公开(公告)日：1993-09-16

申请号：DE3587515

申请日：1985-05-15

Applicant: NEC CORP

Inventor： FUJIWARA MASAHIKO ,  AJISAWA AKIRA ,  SUZUKI SHUJI

IPC: H03K17/785 ,  H04Q3/52 ,  H04B10/12

Abstract: An optical switch circuit is configured as a matrix array to arbitrarily switch the connections between optical transmission channels. The optical switch circuit comprises a plurality of optical splitter coupled to input transmission channels, a plurality of optical switches arranged on the matrix crosspoitns, each switch comprising an optoelectronic element and a light modulating element functioning as an electrooptic element, and a plurality of optical combiners coupled to output transmission channels. Thus, a small-sized optical switch circuit suitable for integration is realized. With this circuit, small crosstalk and high speed switching without distortion of broadband signals are expected. Further, this circuit provides a wide adaptability such that light transmitted through multi-mode optical fiber can be switched.

公开(公告)号：JPH0945953A

公开(公告)日：1997-02-14

申请号：JP19683695

申请日：1995-08-01

Applicant: NEC CORP

Inventor： AJISAWA AKIRA

IPC: H01L31/10

Abstract: PROBLEM TO BE SOLVED: To obtain a photodiode array, for an array infrared detector employing HgCdTe, having excellent characteristics in both bulk part and surface part. SOLUTION: A low carrier concentration p-HgCdTe layer 2 and a high carrier concentration p -HqCdTe layer 3 of the same conductivity type as the p - HgCdTe layer 2 are grown epitaxially on a CdTe substrate 1 and an n-HgCdTe region 4 of opposite conductivity type to the p -HgCdTe layer 2 and p -HgCdTe layer 3 is formed thereon in array. pn junction formed by the n-HgCdTe region 4 is included in the p -HgCdTe layer 3.

公开(公告)号：JPH05160429A

公开(公告)日：1993-06-25

申请号：JP32353391

申请日：1991-12-09

Applicant: NEC CORP

Inventor： AJISAWA AKIRA

IPC: C30B29/68 ,  G01J1/02 ,  H01L27/14 ,  H01L31/10

Abstract: PURPOSE:To obtain a highly sensitive infrared ray sensor, by adopting a sawtooth-like potential structure of a type-II superlattice. CONSTITUTION:An i-InAs1-xSbx superlattice light absorbing layer 13 has a band gap in the wavelength region of 10mum band as its lowest energy level, owing to its composition and potential structure, when infrared light 17 of 10mum band is projected on the p-side of the top part of an infrared ray sensor and reaches the layer 13. The light is absorbed in this layer, and electrons and holes are generated. Though wave functions 2, 3 of hole and electron are separated from each other spatially, since they exist locally near respective interfaces and their overlap is large, the probability of transition of electrons from valence band to conduction band is high. Therefore, more electrons and more holes are generated, and they are respectively attracted by their reverse biases across a p-n junction. As a result, since they reach respective electrodes and are taken out as electric signals respectively, the increase of the absorption coefficient of infrared rays is brought, and a highly sensitive infrared ray sensor is obtained.

公开(公告)号：JPH04318979A

公开(公告)日：1992-11-10

申请号：JP8532391

申请日：1991-04-17

Applicant: NEC CORP

Inventor： AJISAWA AKIRA

IPC: H01L31/0264 ,  H01L31/10

Abstract: PURPOSE:To obtain a sensor which simultaneously satisfies high sensitivity due to a reduction in a dark current and high resolution due to multiple pixels in an array type infrared ray sensor. CONSTITUTION:An n type HgCdTe ion implanted region 4 is formed on a p-type HgCdTe layer 2 by ion implanting, pixels are separated by mesa etching, and an n type HgCdTe diffused region 3 is formed by heat treating. Since a p-n junction position of a photodiode 5 is moved to a region which is not damaged by the ion implantation, a dark current due to a recombination caused by a crystal defect is very small, and a high sensitivity photodiode is obtained. Further, since a mesa type structure is formed and lateral diffusion of the p-n junction by heat treating is suppressed, a pitch between the photodiodes can be reduced, and an array type infrared ray sensor having high resolution is obtained.

公开(公告)号：JPH04192559A

公开(公告)日：1992-07-10

申请号：JP32480690

申请日：1990-11-27

Applicant: NEC CORP

Inventor： AJISAWA AKIRA

IPC: H01L29/41 ,  H01L21/36 ,  H01L27/14 ,  H01L27/146 ,  H01L31/10

Abstract: PURPOSE:To reduce a dark current by a method wherein through holes corresponding to output-signal processing parts in a silicon chip are made in individual photodiodes and the photodiodes are connected electrically to the output- signal processing parts in the chip via the through holes. CONSTITUTION:A compound semiconductor whose forbidden band width is narrow is epitaxially grown linearly on the mirror-finished rear of a silicon chip 3 provided with output-signal processing parts 4; individual photodiodes 6 arranged and formed on the compound semiconductor and the output-signal processing parts 4 in the silicon chip 3 are connected electrically via through holes 7. Consequently, the reliability of electrical interconnections during an operation, i.e., against a violent temperature change, is enhanced. Since the uniformity of the film thickness of the compound semiconductor is good, a dark current is small in all elements and a high-performance characteristic can be obtained. Thereby, it is possible to improve a dark-current characteristic caused by a crystal defect or the like.