IP Library › Granted Patent US 12,346,000
Granted Patent B2
US 12,346,000 · App. 18/004,591 · Granted Jul 1, 2025

Planar optical waveguide device for measuring amplitude phase of squeezed light

Inventors: Asuka Inoue (Musashino, JP); Ryoichi Kasahara (Musashino, JP); Takeshi Umeki (Musashino, JP); Osamu Tadanaga (Musashino, JP); Koji Embutsu (Musashino, JP); Nobutatsu Koshobu (Musashino, JP); Takushi Kazama (Musashino, JP); Takahiro Kashiwazaki (Musashino, JP)
Assignee: Nippon Telegraph and Telephone Corporation
G02F1/365
View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 12,346,000
App. No.
18/004,591
Granted
Jul 1, 2025
Kind
B2
Abstract

A planar optical waveguide device which has improved resistance to optical loss and improved stability of the entire system of balanced homodyne detection is realized. An embodiment is an optical waveguide device for measurement of squeezed light using balanced homodyne detection, including an amplifier circuit that is connected to a signal light input port for inputting the squeezed light and performs phase-sensitive amplification, and a multiplexing/demultiplexing circuit that is connected to a local oscillator optical input port and an output of the amplifier circuit, has local oscillator light and the amplified squeezed light incident on the circuit, and outputs the light interfering with each other to two output ports.

Claims (14)

1. A planar optical waveguide device for measurement of squeezed light using balanced homodyne detection, comprising:

an amplifier circuit connected to a signal light input port for inputting the squeezed light, for performing phase-sensitive amplification; and

a multiplexing/demultiplexing circuit connected to a local oscillator optical input port and an output of the amplifier circuit, for inputting local oscillator light and the amplified squeezed light and outputting the light interfering with each other to two output ports.

2. The planar optical waveguide device according to claim 1 , wherein the amplifier circuit includes:

a first multiplexer/demultiplexer configured to multiplex the squeezed light with excitation light,

a phase-sensitive amplifier connected to the first multiplexer/demultiplexer, for receiving the incident squeezed light and the excitation light and performing phase-sensitive amplification, and

a second multiplexer/demultiplexer configured to demultiplex the amplified squeezed light and the excitation light.

3. The planar optical waveguide device according to claim 2 , wherein the multiplexing/demultiplexing circuit is a multimode interference multiplexer/demultiplexer or a directional coupler type multiplexer/demultiplexer.

4. The planar optical waveguide device according to claim 2 , wherein each of the first multiplexer/demultiplexer and the second multiplexer/demultiplexer is a multimode interference multiplexer/demultiplexer or a directional coupler type multiplexer/demultiplexer.

5. The planar optical waveguide device according to claim 2 , wherein a spot-size converter is arranged at the local oscillator optical input port and two input ports of the first multiplexer/demultiplexer.

6. The planar optical waveguide device according to claim 2 , wherein the phase-sensitive amplifier is formed of at least one of LiNbO 3 , KNbO 3 , LiTaO 3 , LiNb (x) Ta (1-x) O 3 (0≤x≤1)), or KTiOPO 4 , or one of these optical materials containing at least one type selected from the group consisting of Mg, Zn, Sc, and In as an additive.

7. The planar optical waveguide device according to claim 6 , wherein the phase-sensitive amplifier is made of the optical material in which a periodic polarization inversion structure is formed.

8. The planar optical waveguide device according to claim 1 , further comprising:

a phase control mechanism inserted between the local oscillator optical input port and the multiplexing/demultiplexing circuit.

Assignments (2)
CHANGE OF NAME Recorded Aug 18, 2025
From: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
To: NTT, INC.
Reel/Frame 072507/0679 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 6, 2023
From: INOUE, ASUKA; KASAHARA, RYOICHI; UMEKI, TAKESHI; TADANAGA, OSAMU; EMBUTSU, KOJI; KOSHOBU, NOBUTATSU; KAZAMA, TAKUSHI; KASHIWAZAKI, TAKAHIRO
To: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Reel/Frame 062301/0152 →
Continuity (1)
Related Publication 20230251549A1 · Aug 10, 2023
References Cited (12)
US 5113524A · Hirota et al. · 1992 [cited by applicant]
US 10082623B2 · Kato · 2018 [cited by examiner]
US 10498102B2 · Akasaka · 2019 [cited by examiner]
JP H01231033A · 1989 [cited by applicant]
JP H0293524A · 1990 [cited by applicant]
JP H03192929A · 1991 [cited by applicant]
JP 2014123009A · 2014 [cited by applicant]
WO 2014017154A1 · 2014 [cited by applicant]
Manceau. M, et al. [cited by applicant]
Takushi Kazama et al., [cited by applicant]
Hideki Tsunetsugu et al., [cited by applicant]
Naoto Takanashi et al., [cited by applicant]