公开(公告)号：US20230353249A1

公开(公告)日：2023-11-02

申请号：US18019280

申请日：2020-09-01

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Toshiaki SHITABA ,  Tomoaki YOSHIDA ,  Akihiro TANABE ,  Takashi MITSUI

IPC: H04B10/516 ,  H04B10/50

CPC classification number: H04B10/516 ,  H04B10/503

Abstract: An optical transmission device includes a distribution unit which generates a first modulated signal and a second modulated signal by distribution processing for an input signal; a first phase modulator which generates a first optical signal phase-modulated in accordance with the first modulated signal by using a laser beam based on a first oscillation frequency; a phase adjustment unit which generates the second modulated signal of a phase opposite to a phase of the first modulated signal; a second phase modulator which generates a second optical signal phase-modulated in accordance with the second modulated signal of the opposite phase by using a laser beam based on a second oscillation frequency; a multiplexing unit which multiplexes the first optical signal and the second optical signal; and a detection unit which generates a frequency-modulated signal by performing square-law detection processing on a result of multiplexing.

公开(公告)号：US20230135622A1

公开(公告)日：2023-05-04

申请号：US17910919

申请日：2020-03-13

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Akihiro TANABE ,  Takashi MITSUI ,  Toshiaki SHITABA ,  Tomoaki YOSHIDA

IPC: H04B10/032 ,  H04B10/61

Abstract: An optical transmission apparatus includes an input unit, a demultiplexing unit, a measurement unit, and a switching unit. The input unit inputs a first multiplexed signal and a second multiplexed signal each obtained by multiplexing a plurality of optical signals having different wavelengths. The demultiplexing unit demultiplexes the first multiplexed signal and the second multiplexed signal by wavelength. The measurement unit measures qualities of a plurality of optical signals obtained by demultiplexing the first multiplexed signal and qualities of a plurality of optical signals obtained by demultiplexing the second multiplexed signal. The switching unit performs switching between the first multiplexed signal and the second multiplexed signal to be output to a subsequent stage based on a result of measurement by the measurement unit.

公开(公告)号：US20230099159A1

公开(公告)日：2023-03-30

申请号：US17911027

申请日：2020-03-13

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Akihiro TANABE ,  Takashi MITSUI ,  Tomoaki YOSHIDA ,  Toshiaki SHITABA

IPC: H04B10/61 ,  H04B10/572 ,  H04B10/294

Abstract: An optical transmission apparatus of an embodiment is an apparatus for redundantly transmitting a multiplexed signal obtained by multiplexing N (N is an integer of 2 or greater) optical signals having different wavelengths, the apparatus including: a first demultiplexing unit to which a first multiplexed signal is input, the first demultiplexing unit configured to demultiplex the input first multiplexed signal into the N optical signals; N first detection units to which the N optical signals demultiplexed by the first demultiplexing unit are respectively input, each of the N first detection units configured to detect presence or absence of deterioration of a corresponding input optical signals of the input optical signals based on a signal level of the corresponding input optical signal; a second demultiplexing unit to which a second multiplexed signal is input, the second demultiplexing unit configured to demultiplex the input second multiplexed signal into the N optical signals; N second detection units to which the N optical signals demultiplexed by the second demultiplexing unit are respectively input, each of the N second detection units configured to detect presence or absence of deterioration of a corresponding input optical signal of the input optical signals based on a signal level of the corresponding input optical signal; and a selection unit configured to select, based on the detection result of presence or absence of deterioration of each of the optical signals by the first detection units and the second detection units, N optical signals having different wavelengths from either the optical signals demultiplexed by the first demultiplexing unit or the optical signals demultiplexed by the second demultiplexing unit.

公开(公告)号：US20240162991A1

公开(公告)日：2024-05-16

申请号：US18281773

申请日：2021-04-01

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Ryo MIYATAKE ,  Yoichi FUKADA ,  Toshiaki SHITABA ,  Akihiro TANABE ,  Tomoaki YOSHIDA

IPC: H04B10/516 ,  H04B10/50 ,  H04J14/00

CPC classification number: H04B10/5161 ,  H04B10/503 ,  H04J14/00

Abstract: An optical transmission device includes: a first optical phase modulator that outputs a first optical signal by phase-modulating the laser beam having a first oscillation frequency according to the first electric signal in a case where the first electric signal is output to the first transmission path, a second optical phase modulator that outputs a laser beam having a second oscillation frequency as the second optical signal in a case where the first electric signal is output to the first transmission path; an optical multiplexer/distributor that outputs a third optical signal and a fourth optical signal by multiplexing the first optical signal and the second optical signal and distributing a result of the multiplexing; a first detection unit that converts the third optical signal into a first heterodyne detection signal; a second detection unit that converts the fourth optical signal into a second heterodyne detection signal; and a first optical intensity modulator that intensity-modulates a laser beam having a third oscillation frequency according to one of the first heterodyne detection signal and the second heterodyne detection signal.

公开(公告)号：US20240063916A1

公开(公告)日：2024-02-22

申请号：US18270537

申请日：2021-01-04

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Toshiaki SHITABA ,  Akihiro TANABE ,  Yoichi FUKADA ,  Ryo MIYATAKE

IPC: H04B10/548 ,  H04B10/50

CPC classification number: H04B10/548 ,  H04B10/503

Abstract: An optical transmission apparatus includes:



a distribution unit configured to distribute a modulation signal to a plurality of amplification units connected in parallel; a plurality of phase modulators which are connected in cascade to generate a phase-modulated optical signal in accordance with each modulation signal of which voltage is amplified by the plurality of amplification units connected in parallel by using a laser beam based on a first oscillation frequency; a multiplexing unit configured to multiplex a laser beam based on a second oscillation frequency and the optical signal; and a detection unit configured to generate a frequency modulation signal by executing detection processing on a result of multiplexing the laser beam based on the second oscillation frequency and the optical signal.

公开(公告)号：US20240056193A1

公开(公告)日：2024-02-15

申请号：US18269491

申请日：2020-12-28

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Akihiro TANABE ,  Toshiaki SHITABA ,  Yoichi FUKADA ,  Ryo MIYATAKE ,  Tomoaki YOSHIDA

IPC: H04B10/516

CPC classification number: H04B10/516

Abstract: An optical transmission device includes: an FM batch conversion unit that performs FM batch conversion on a carrier signal input from the outside, to generate an FM batch conversion signal; a signal branching unit that causes the FM batch conversion signal to branch into a first path and a second path; an optical transmission unit that is provided in the first path, converts the FM batch conversion signal into an optical signal, and transmits the optical signal to the outside; and a detection unit that is provided in the second path, and detects quality degradation of the FM batch conversion signal on the basis of the signal level of the FM batch conversion signal.

公开(公告)号：US20230370167A1

公开(公告)日：2023-11-16

申请号：US18026409

申请日：2020-09-18

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Akihiro TANABE ,  Toshiaki SHITABA ,  Yoichi FUKADA ,  Tomoaki YOSHIDA

IPC: H04B10/54

CPC classification number: H04B10/54

Abstract: A signal converting apparatus includes a conversion unit, a measurement unit, and a control unit. The conversion unit performs FM batch conversion on an input signal containing a plurality of carrier signals, to generate an FM signal. The measurement unit measures the carrier levels of the plurality of carrier signals contained in the input signal, and the maximum frequency of the input signal. The control unit calculates the frequency deviation amount of the entire input signal, on the basis of the measured carrier levels of the respective carrier signals. Using the calculated frequency deviation amount and the measured maximum frequency, the control unit calculates a center frequency for the FM signal, and controls the conversion unit so that the center frequency of the FM signal to be generated by the FM batch conversion becomes equal to the calculated center frequency.

公开(公告)号：US20250080223A1

公开(公告)日：2025-03-06

申请号：US18726016

申请日：2022-01-11

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Toshiaki SHITABA ,  Tomoaki YOSHIDA ,  Yoichi FUKADA ,  Akihiro TANABE ,  Ryo MIYATAKE

IPC: H04B10/2507 ,  H04B10/079

Abstract: An optical receiving apparatus includes: a first branching unit that branches an input optical signal into a first optical signal and a second optical signal; a reception amplification unit that amplifies power of the first optical signal; a compensation unit that compensates for wavelength distortion of the first optical signal whose power has been amplified; a first detection unit that detects power of the second optical signal; a first control unit that controls an amount of compensation for the wavelength distortion on the basis of the power of the second optical signal; a second branching unit that branches the first optical signal compensated for the wavelength distortion into a third optical signal and a fourth optical signal; a second detection unit that detects power of the third optical signal; and a second control unit that controls an amplification factor of the power of the first optical signal before the compensation for the wavelength distortion on the basis of the power of the third optical signal.

公开(公告)号：US20240421910A1

公开(公告)日：2024-12-19

申请号：US18274148

申请日：2021-02-10

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Toshiaki SHITABA ,  Tomoaki YOSHIDA ,  Yoichi FUKADA ,  Akihiro TANABE ,  Ryo MIYATAKE

IPC: H04B10/516 ,  H04J14/02

Abstract: An optical transmission apparatus includes: a distributing unit which distributes a laser beam based on a first oscillation frequency; a phase modulator which generates, using the laser beam based on the first oscillation frequency, a phase-modulated signal that is an optical signal phase-modulated in accordance with a modulated signal; a multiplexing unit which multiplexes a laser beam based on a second oscillation frequency and the phase-modulated signal; a detecting unit which generates a frequency-modulated signal by performing detection processing on a result of multiplexing of the laser beam based on the second oscillation frequency and the phase-modulated signal; and an intensity modulator which generates, using the laser beam based on the first oscillation frequency, an optical signal intensity-modulated in accordance with the frequency-modulated signal.

公开(公告)号：US20240356654A1

公开(公告)日：2024-10-24

申请号：US18683712

申请日：2021-08-25

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Toshiaki SHITABA ,  Tomoaki YOSHIDA ,  Yoichi FUKADA ,  Akihiro TANABE ,  Ryo MIYATAKE

IPC: H04B10/54 ,  H04B10/508 ,  H04J1/00

CPC classification number: H04B10/54 ,  H04B10/508 ,  H04J1/00

Abstract: There is provided a signal amplification method executed by an optical reception device, the method including: an electrical conversion step of converting an optical intensity modulation signal according to a frequency modulation signal which is converted from a frequency division multiplexing signal into the frequency modulation signal; a delay control step of controlling a delay amount of the frequency modulation signal based on a center frequency of the frequency modulation signal and a shift amount of a highest frequency of the frequency modulation signal; a delay detection step of demodulating the frequency modulation signal into the frequency division multiplexing signal by executing demodulation processing based on delay detection on the frequency modulation signal of which the delay amount is controlled; an amplification factor derivation step of deriving an amplification factor of the demodulated frequency division multiplexing signal based on the delay amount; and an amplification step of amplifying the demodulated frequency division multiplexing signal by the amplification factor.