# US 11,909,448 B2 · Single-fiber bi-directional optical transceiver sub-assembly

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- Number: US 11,909,448 B2
- Document ID: US11909448B2
- Status: Granted
- Kind: B2
- Application number: 17/439,519
- Filed: 2019-11-22
- Published: 2022-05-19
- Granted: 2024-02-20
- Earliest claimed: 2019-03-27
- Assignees: NEC Corporation
- Applicants: NEC Corporation
- Inventors: Isao Tomita
- Web page: https://patentgrep.com/patent/US11909448B2

## CPC

- G02B 6/3822: {with beveled fibre ends}
- H04B 10/40: Transceivers
- G02B 6/4206: {Optical features (G02B6/4207, G02B6/421 take precedence)}
- G02B 6/4215: {the intermediate optical elements being wavelength selective optical elements, e.g. variable wavelength optical modules or wavelength lockers (G02B6/4246 takes precedence)}
- G02B 6/4246: {Bidirectionally operating package structures}
- G02B 6/4292: {the light guide being disconnectable from the opto-electronic element, e.g. mutually self aligning arrangements}
- H04B 10/2581: Multimode transmission
- H10F 77/40: Optical elements or arrangements (surface textures H10F77/70)
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- H04B: TRANSMISSION
- H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION

## Abstract

Provided is a single-fiber bi-directional optical transceiver sub-assembly capable of improving the wavelength separation characteristics of a multiplexing/demultiplexing filter while also attaining a compact size. A single-fiber bi-directional optical transceiver sub-assembly is provided with a housing, an optical receptacle, a multiplexing/demultiplexing filter, a receiving-side photoelectric converter, a transmitting-side photoelectric converter, an isolator, and a collimating lens. The multiplexing/demultiplexing filter is disposed on the optical path between the optical receptacle and the transmitting-side photoelectric converter and on the optical path between the optical receptacle and the receiving-side photoelectric converter. The isolator passes optical signals outputted from the transmitting-side photoelectric converter and blocks optical signals proceeding to the transmitting-side photoelectric converter. The collimating lens is disposed at a position that fits into the external size of the housing, and collimates incident light on the multiplexing/demultiplexing filter.

## Claims

### Claim 1

A single-fiber bi-directional optical transceiver sub-assembly comprising:
a housing;
an optical receptacle;
a transmitting-side photoelectric converter;
a receiving-side photoelectric converter;
a multiplexing/demultiplexing filter disposed on an optical path between the optical receptacle and the transmitting-side photoelectric converter and on an optical path between the optical receptacle and the receiving-side photoelectric converter;
an isolator configured to pass an optical signal outputted from the transmitting-side photoelectric converter and block an optical signal proceeding to the transmitting-side photoelectric converter;
a first collimating lens, disposed on an optical axis between the optical receptacle and the multiplexing/demultiplexing filter, disposed at a position that fits into an external size of the housing, and configured to collimate incident light on the multiplexing/demultiplexing filter; and
a second collimating lens disposed on an optical axis between the transmitting-side photoelectric converter and the multiplexing/demultiplexing filter, wherein
the first collimating lens is disposed at a position within a width along a first direction of the receiving-side photoelectric converter, the first direction being an optical axis direction of the optical receptacle,
the isolator is disposed on the optical axis between the transmitting-side photoelectric converter and the multiplexing/demultiplexing filter, and
the second collimating lens is disposed on an optical axis between the transmitting-side photoelectric converter and the isolator.

### Claim 2 (depends on 1)

The single-fiber bi-directional optical transceiver sub-assembly according to claim 1, further comprising a first holder configured to hold the first collimating lens,
wherein at least a portion of the first holder is disposed at a position that fits into the external size of the housing.

### Claim 3 (depends on 1)

The single-fiber bi-directional optical transceiver sub-assembly according to claim 1, wherein the second collimating lens is disposed at a position that fits into the external size of the housing.

### Claim 4 (depends on 3)

The single-fiber bi-directional optical transceiver sub-assembly according to claim 3, further comprising a second holder configured to hold the second collimating lens,
wherein a portion of the second holder is disposed at a position that fits into the external size of the housing.

### Claim 5 (depends on 1)

The single-fiber bi-directional optical transceiver sub-assembly according to claim 1, further comprising a third
collimating lens disposed on an optical axis between the receiving-side photoelectric converter and the multiplexing/demultiplexing filter.

### Claim 6 (depends on 5)

The single-fiber bi-directional optical transceiver sub-assembly according to claim 5, wherein the third collimating lens is disposed at a position that fits into the external size of the housing.

### Claim 7 (depends on 6)

The single-fiber bi-directional optical transceiver sub-assembly according to claim 6, further comprising a third holder configured to hold the third collimating lens,
wherein a portion of the third holder is disposed at a position that fits into the external size of the housing.

### Claim 8 (depends on 1)

The single-fiber bi-directional optical transceiver sub-assembly according to claim 1, wherein the transmitting-side photoelectric converter, the second collimating lens, the isolator, the multiplexing/demultiplexing filter, and the first collimating lens are linearly arranged on a same optical path.