Optical pulse generator and generation method

Patent metadata

Field	Value
Publication number	US-2025112694-A1
Application number	US-202218729208-A
Country	US
Kind code	A1
Filing date	Jan 25, 2022
Priority date	Jan 25, 2022
Publication date	Apr 3, 2025
Grant date	—

Abstract

A light pulse generation device includes a light intensity modulator 2 that outputs light pulses in which a signal intensity of a photocarrier output by a light source 1 is modulated in accordance with a magnitude of a drive signal with an operation bias point as the center, a measurement unit 3 that measures an inter-pulse phase component that is an amplitude between the light pulses, a bias control unit 4 that controls the operation bias point on the basis of a magnitude of the inter-pulse phase component, and a drive signal control unit 5 that controls the magnitude of the drive signal on the basis of the magnitude of the inter-pulse phase component. The drive signal control unit 5 controls the drive signal such that an amplitude of the drive signal is twice an amplitude between a maximum value and a minimum value of a transmission characteristic of the light intensity modulator 2.

First claim

1 . A light pulse generation device comprising:
a light intensity modulator that outputs light pulses in which a signal intensity of a photocarrier output by a light source is modulated in accordance with a magnitude of a drive signal with an operation bias point as the center; a measurement unit that measures an inter-pulse phase component that is an amplitude between the light pulses; a bias control unit that controls the operation bias point on the basis of a magnitude of the inter-pulse phase component; and a drive signal control unit that controls the magnitude of the drive signal on the basis of the magnitude of the inter-pulse phase component.

2 . The light pulse generation device according to claim 1 , wherein
the drive signal control unit controls the drive signal such that an amplitude of the drive signal is twice an amplitude between a maximum value and a minimum value of a transmission characteristic of the light intensity modulator.

3 . The light pulse generation device according to claim 1 , wherein
the bias control unit performs control to set the operation bias point to the maximum value of the transmission characteristic of the light intensity modulator.

4 . The light pulse generation device according to claim 1 , wherein
the measurement unit includes a phase separation unit that extracts the inter-pulse phase component, and a light intensity measurement unit that measure an intensity of an optical signal output by the phase separation unit.

5 . The light pulse generation device according to claim 4 , wherein
the phase separation unit includes a Mach-Zehnder interferometer to which the light pulse is input.

6 . The light pulse generation device according to claim 5 , wherein
the Mach-Zehnder interferometer includes a first Mach-Zehnder interferometer that delays a time of one cycle of a frequency of the light pulse, and a second Mach-Zehnder interferometer that is connected to an output of the first Mach-Zehnder interferometer and delays a time of a cycle of ½ of the frequency.

7 . A light pulse generation method comprising:
a light intensity modulation step of outputting light pulses in which a signal intensity of a photocarrier output by a light source is modulated in accordance with a magnitude of a drive signal with an operation bias point as the center; a measurement step of measuring an inter-pulse phase component that is an amplitude between the light pulses; a bias control step of controlling the operation bias point on the basis of a magnitude of the inter-pulse phase component; and a drive signal control step of controlling the magnitude of the drive signal on the basis of the magnitude of the inter-pulse phase component.

8 . The light pulse generation method according to claim 7 , comprising:
a test signal transmission step of transmitting, to a receiver, a test signal indicating that either the drive signal control step or the bias control step is being performed; and a test signal notification step of notifying the receiver of a start position of the test signal.

Assignees

• Nippon Telegraph & Telephone

Inventors

• Taniguchi Atsushi
• Nishizawa Hideki
• Obana Kazuaki

Classifications

• H04B10/54

  Intensity modulation · CPC title

• H04B10/073 Primary

  using an out-of-service signal (H04B10/071 takes precedence) · CPC title

• G02F1/01

  for the control of the intensity, phase, polarisation or colour  (G02F1/29, G02F1/35 take precedence) · CPC title

• G02F1/225

  in an optical waveguide structure · CPC title