Variable dual-directional thermal compensator for arrayed waveguide grating (AWG) modules

Patent metadata

Field	Value
Publication number	US-11619780-B2
Application number	US-201917430971-A
Country	US
Kind code	B2
Filing date	Feb 28, 2019
Priority date	Feb 28, 2019
Publication date	Apr 4, 2023
Grant date	Apr 4, 2023

Abstract

A thermal compensator, for use in connection with arrayed waveguide grating (AWG) modules which are, in turn, utilized in conjunction with wavelength multiplexing and de-multiplexing within optical networks, is disclosed. The thermal compensator comprises a bow-shaped frame member, a central bar member, and a screw. The bow-shaped frame member is characterized by a higher or great coefficient of thermal expansion (CTE) than that of the central bar member such that the bow-shaped frame member can expand and elongate at a greater rate than can the central bar member under hot temperature conditions, however, under cold temperature conditions, the rate of contraction of the bow-shaped member is effectively retarded by the slower rate of contraction of the central bar member. The bow-shaped frame member is adapted to be attached to a movable section of an athermal arrayed waveguide grating (AAWG) module such that the expansion and contraction movements of the bow-shaped member influence the movement of a movable section of the athermal arrayed waveguide grating (AAWG) module in order to maintain the proper focus of the athermal arrayed waveguide grating (AAWG) module across disparate temperature conditions within which the athermal arrayed waveguide grating (AAWG) module is designed to operate.

First claim

What is claimed is:

1. A thermal compensator for use in conjunction with an athermal arrayed waveguide grating (AAWG) module utilized for achieving wavelength multiplexing and de-multiplexing within optical networks, comprising:
a bow-shaped frame member adapted to be connected to an athermal arrayed waveguide grating (AAWG) module; and
a central bar member attached having a first end portion attached to a first end section of said bow-shaped frame member;
wherein said bow-shaped frame member is fabricated from a first predetermined material which has a first coefficient of thermal expansion (CTE), and said central bar member is fabricated from a second predetermined material which has a second coefficient of thermal expansion (CTE) which is less than said first coefficient of thermal expansion (CTE) of said first predetermined material comprising said bow-shaped frame member.

2. The thermal compensator as set forth in claim 1 , wherein:
under relatively high temperature conditions, said bow-shaped frame member will expand at a greater rate than will said central bar member, whereas under relatively low temperature conditions, contraction of said central bar member, at a rate slower than the contraction of said bow-shaped frame member, will effectively retard the contraction of said bow-shaped frame member.

3. The thermal compensator as set forth in claim 2 , wherein:
under said relatively high or relatively low temperature conditions, said bow-shaped frame member will expand and contract such that the incoming light path, of light coming into said athermal arrayed waveguide grating (AAWG) module, will experience an angular shift which is less than a predetermined range or error relative to the incoming light path under average temperature conditions.

4. The thermal compensator as set forth in claim 1 , wherein:
said bow-shaped frame member defines a central hollow portion within which said central bar member is disposed.

5. The thermal compensator as set forth in claim 1 , further comprising:
a screw having a first end portion thereof threadedly engaged within a second opposite end section of said bow-shaped frame member and a second end portion engaged with a second end portion of said central bar member such that said second end portion of said central bar member will be disposed in engagement with said screw when said thermal compensator has fully contracted under cold temperature conditions.

6. The thermal compensator as set forth in claim 1 , wherein:
said central bar member has a substantially T-shaped configuration with a transversely oriented head section of said T-shaped central bar member engaged with said first end section of said bow-shaped frame member, while a foot section of said T-shaped central bar member engaged with said second end portion of said threadedly adjustable screw.

7. The thermal compensator as set forth in claim 5 , wherein:
said screw is fabricated from a predetermined material having a Young's Modulus greater than the Young's Modulus of said central bar member; and
a protection block, fabricated from a predetermined material having a Young's Modulus which is substantially the same as the Young's Modulus of said screw, is fixedly secured to said second end portion of said central bar member such that said screw cannot damage said central bar member when said second end portion of said central bar member is engage with said second end portion of said screw.

8. The thermal compensator as set forth in claim 1 , further comprising:
an expansion-enhancement block fixedly secured to an external surface portion of said first end section of said bow-shaped frame member, wherein said expansion-enhancement block is fabricated from a predetermined material which has a coefficient of thermal expansion (CTE) which is greater than the coefficient of thermal expansion (CTE) of said bow-shaped frame member such that said first end section of said bow-shaped frame member can expand at a greater rate than other sections of said bow-shaped frame member.

9. The thermal compensator as set forth in claim 1 , wherein:
said bow-shaped member comprises leg portions which are effectively mirror-images of each other.

10. The thermal compensator as set forth in claim 1 , wherein:
said bow-shaped member has a substantially hexagonal configuration.

11. The thermal compensator as set forth in claim 1 , wherein:
said bow-shaped frame member has a substantially diamond-shaped configuration.

12. The thermal compensator as set forth in claim 1 , wherein:
said bow-shaped member has a pair of leg members interconnecting said first and second end sections together; and
wherein both of said pair of leg members are arcuately configured.

13. The thermal compensator as set forth in claim 1 , wherein:
said bow-shaped member has a pair of leg members interconnecting said first and second end sections together; and
wherein a first one of said pair of leg members is arcuately configured while the second one of said pair of leg members comprises one half of a diamond.

14. The thermal compensator as set forth in claim 4 , wherein:
said bow-shaped member has a pair of leg members interconnecting said first and second end sections together; and
wherein both of said pair of leg members define sides of said hexagon but have portions which vary in thickness.

15. The thermal compensator as set forth in claim 6 , wherein:
said bow-shaped member has a pair of leg members interconnecting said first and second end sections together; and
said first end section of said bow-shaped frame member is provided with a chamber for accommodate said head portion of said T-shaped central bar member.

16. The thermal compensator as set forth in claim 1 , wherein:
said central bar member has a configuration which is selected from the group comprising a cylindrical rod having a circular cross-section, a rod forming a rectangular parallelepiped, a substantially T-shaped configuration comprising a body portion and a transversely oriented head section wherein said head section of said T-shaped central bar member has a width dimension which is only approximately one half the width dimension of said body portion, a substantially T-shaped configuration comprising a body portion and a transversely oriented head section wherein said head section of said T-shaped central bar member has a approximately one corner or one quadrant removed from said head section, and a substantially T-shaped configuration comprising a body portion, extending along a longitudinal axis, and a transversely oriented head section wherein said body portion projects a predetermined distance beyond the axial disposition of said head section of said T-shaped central bar member, upon said body portion of said T-shaped central bar member, as considered along said longitudinal axis of said body portion.

17. The thermal compensator as set forth in claim 1 , wherein:
said bow-shaped frame member and said central bar member may be fabricated from any material exhibiting predetermined coefficients of thermal expansion (CTE) so as to achieve optimum expansion and contraction results, wherein said material is selected from the group comprising steel, iron, stainless steel, copper, aluminum, nickel, zinc, cobalt, magnesium, kovar, brass, lead, graphite, carbon, rubber, ceramic, wood, epoxy, anodized aluminum, tin, gold, palladium, silver, molybdenum, platinum, titanium, chromium, manganese, various plastics, alloys, polytetrafluoroethylene, polycarbonate, and vinyl.

18. An athermal arrayed waveguide grating (AA

Assignees

• Molex Llc

Inventors

• Zhang Shuyu
• Lee Glenn
• Huang Mike Chia
• Huang Taizhong

Classifications

• G02B6/1203 Primary

  using mounting means, e.g. by using a combination of materials having different thermal expansion coefficients · CPC title

• G02B6/4215

  the intermediate optical elements being wavelength selective optical elements, e.g. variable wavelength optical modules or wavelength lockers (G02B6/4246 takes precedence) · CPC title

• G02B6/12011

  characterised by the arrayed waveguides, e.g. comprising a filled groove in the array section · CPC title

• G02B6/4267 Primary

  Reduction of thermal stress, e.g. by selecting thermal coefficient of materials · CPC title

• G02B6/12033

  characterised by means for configuring the device, e.g. moveable element for wavelength tuning (switching G02B6/35; thermo-optic devices G02F1/0147) · CPC title