Wavelength-division multiplexing devices with modified angles of incidence

Patent metadata

Field	Value
Publication number	US-11474299-B2
Application number	US-202117158688-A
Country	US
Kind code	B2
Filing date	Jan 26, 2021
Priority date	Jul 31, 2018
Publication date	Oct 18, 2022
Grant date	Oct 18, 2022

Abstract

Disclosed herein are wavelength-division multiplexing devices using different angles of incidence (AOIs) at the WDM filters to provide for variable placement and orientation of WDM filters and channel ports, thereby decreasing the device footprint and allowing for shorter overall optical signal paths to increase signal performance and reliability. Also disclosed are stacked WDM filters for increased signal isolation.

First claim

What is claimed is:

1. A method of using a wavelength-division multiplexing (WDM) device, comprising:
transmitting from a common collimator a multiplexed signal comprising a first signal, a second signal, a third signal, a fourth signal, and a fifth signal;
intersecting the multiplexed signal at a first angle of incidence (AOI) at a first WDM filter;
passing the first signal through the first WDM filter to a first channel collimator so that the multiplexed signal becomes a first remaining multiplexed signal;
reflecting the first remaining multiplexed signal from the first WDM filter to a second WDM filter;
intersecting the first remaining multiplexed signal at a second AOI at the second WDM filter;
passing the second signal through the second WDM filter to a second channel collimator so that the first remaining multiplexed signal becomes a second remaining multiplexed signal;
reflecting the second remaining multiplexed signal from the second WDM filter to a third WDM filter;
intersecting the second remaining multiplexed signal at a third AOI at the third WDM filter;
passing the third signal through the third WDM filter to a third channel collimator so that the second remaining multiplexed signal becomes a third remaining multiplexed signal that comprises the fourth signal and the fifth signal;
reflecting the third remaining multiplexed signal from the third WDM filter to a fourth WDM filter;
intersecting the third remaining multiplexed signal at a fourth AOI at the fourth WDM filter;
passing the fourth signal through the fourth WDM filter to a fourth channel collimator;
reflecting the fifth multiplexed signal from the fourth WDM filter to a fifth WDM filter that is configured to pass the fifth signal;
passing the fifth signal through the fifth WDM filter to a fifth channel collimator;
wherein the first WDM filter and the third WDM filter are aligned along a first axis;
wherein the second WDM filter and the fourth WDM filter are aligned along a second axis that is parallel to and offset from the first axis;
wherein the fourth AOI is different than the third AOI; and
wherein the fifth WDM filter is positioned between the first axis and the second axis such that the optical signal path between the fourth WDM filter and the fifth WDM filter is smaller than the optical signal path between the first WDM filter and the second WDM filter.

2. A wavelength-division multiplexing (WDM) device, comprising:
a common port for optical communication of a multiplexed signal;
a first channel port for optical communication of a first signal of the multiplexed signal;
a second channel port for optical communication of a second signal of the multiplexed signal;
a third channel port for optical communication of a third signal of the multiplexed signal;
a fourth channel port for optical communication of a fourth signal of the multiplexed signal;
a fifth channel port for optical communication of a fifth signal of the multiplexed signal;
an optical signal path between the common port, the first channel port, the second channel port, the third channel port, and the fourth channel port;
a first WDM filter configured to pass the first signal and to reflect the second signal, the third signal, and the fourth signal, the optical signal path intersecting the first WDM filter at a first angle of incidence (AOI);
a second WDM filter configured to pass the second signal and reflect the third signal and the fourth signal, the optical signal path intersecting the second WDM filter at a second AOI;
a third WDM filter configured to pass the third signal and to reflect the fourth signal, the optical signal path intersecting the third WDM filter at a third AOI;
a fourth WDM filter configured to pass the fourth signal, the optical signal path intersecting the fourth WDM filter at a fourth AOI;
a fifth WDM filter configured to pass the fifth signal, the optical signal path intersecting the fifth WDM filter at a fifth AOI;
wherein the first WDM filter and the third WDM filter are aligned along a first axis;
wherein the second WDM filter and the fourth WDM filter are aligned along a second axis that is parallel to and offset from the first axis; and
wherein the fifth WDM filter is positioned between the first axis and the second axis such that the optical signal path between the fourth WDM filter and the fifth WDM filter is smaller than the optical signal path between the first WDM filter and the second WDM filter.

3. The WDM device of claim 2 , wherein the fourth AOI is different than the third AOI, and wherein the fifth AOI is equal to the fourth AOI.

4. The WDM device of claim 3 , wherein a filtering surface of the fifth WDM filter and a filtering surface of the fourth WDM filter are parallel.

5. The WDM device of claim 3 , wherein the multiplexed signal further comprises a sixth signal and wherein the WDM device further comprises:
a sixth channel port for optical communication of a sixth signal of the multiplexed signal; and
a sixth WDM filter configured to pass the sixth signal, the optical signal path intersecting the sixth WDM filter at a sixth AOI;
wherein the sixth AOI is different than the fifth AOI.

6. The WDM device of claim 5 , wherein the sixth AOI is larger than the fifth AOI.

7. The WDM device of claim 5 , wherein a filtering surface of the sixth WDM filter and a filtering surface of the fifth WDM filter are non-parallel.

8. The WDM device of claim 5 , wherein the optical signal path between the fifth WDM filter and the sixth WDM filter is smaller than the optical signal path between the first WDM filter and the second WDM filter.

9. The WDM device of claim 5 , wherein the multiplexed signal further comprises a seventh signal and wherein the WDM device further comprises:
a seventh channel port for optical communication of a seventh signal of the multiplexed signal; and
a seventh WDM filter configured to pass the seventh signal, the optical signal path intersecting the seventh WDM filter at a seventh AOI;
wherein the seventh AOI is equal to the sixth AOI.

10. The WDM device of claim 9 , wherein a filtering surface of the seventh WDM filter and a filtering surface of the sixth WDM filter are parallel.

11. The WDM device of claim 9 , wherein the optical signal path between the sixth WDM filter and the seventh WDM filter is smaller than the optical signal path between the first WDM filter and the second WDM filter.

12. The WDM device of claim 9 , wherein:
the second WDM filter, the fourth WDM filter, and the sixth WDM filter are aligned; and
the third WDM filter, the fifth WDM filter, and the seventh WDM filter are not aligned.

13. The WDM device of claim 2 , wherein the first AOI is equal to the second AOI and the third AOI, and wherein the fourth AOI is larger than the third AOI.

14. The WDM device of claim 2 , wherein:
a filtering surface of the first WDM filter, a filtering surface of the second WDM filter, and a filtering surface of the third WDM filter are parallel; and
a filtering surface of the fourth WDM filter and the filtering surface of the third WDM filter are non-parallel.

Assignees

• Alliance Fiber Optics Prod Inc

Inventors

• Gui Dong
• Li Yao
• Xiao Shudong
• Zhou Andy Fenglei

Classifications

• G02B6/29367 Primary

  Zigzag path within a transparent optical block, e.g. filter deposited on an etalon, glass plate, wedge acting as a stable spacer · CPC title

• G02B6/29311

  Diffractive element operating in transmission · CPC title

• G02B6/2938

  for multiplexing or demultiplexing, i.e. combining or separating wavelengths, e.g. 1xN, NxM · CPC title

• G02B6/3514

  the reflective optical element moving along a line so as to translate into and out of the beam path, i.e. across the beam path · CPC title

• H04J14/02 Primary

  Wavelength-division multiplex systems · CPC title