Optical multiplexer and demultiplexer and a method for fabricating and assembling the multiplexer/demultiplexer

Patent metadata

Field	Value
Publication number	US-9323065-B2
Application number	US-201314068827-A
Country	US
Kind code	B2
Filing date	Oct 31, 2013
Priority date	Oct 31, 2013
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

Known semiconductor wafer process technologies are used to manufacture an optical MUX/DeMUX with very precise dimensional control. The manufacturing process eliminates the need to polish optical surfaces of the MUX/DeMUX, which reduces the overall manufacturing costs and the amount of time that is required to manufacture the MUX/DeMUX.

First claim

What is claimed is:

1. An optical multiplexer (MUX) comprising:
a base having at least an upper surface and a lower surface;
N light sources mounted on the upper surface of the base, where N is an integer that is greater than or equal to two, each light source emitting a light beam of a particular operating wavelength (WL), and wherein the operating WLs are different from one another;
a lens mounted on the upper surface of the base, the lens collimating each of a respective one of the light beams received from the N light sources into N respective collimated light beams; and
a filter block mounted on the upper surface of the base, the filter block arranged to receive the N collimated light beams from the lens along N parallel input optical pathways and to redirect each of the N collimated light beams along a main optical pathway that extends from a first end of the filter block to an opposing end of the filter block and is oriented orthogonal to the N parallel input optical pathways, the filter block including at least a first high pass filter and a second high pass filter, each of which is disposed in the main optical pathway, the first high pass filter arranged to pass a first wavelength of light in at least one of the redirected N collimated light beams while blocking a second wavelength of light in the at least one of the redirected N collimated light beams, the second high pass filter arranged to pass each of the first wavelength of light and the second wavelength of light in the at least one of the redirected N collimated light beams while blocking a third wavelength of light in the at least one of the redirected N collimated light beams.

2. The optical MUX of claim 1 , wherein the filter block further comprises:
a first reflector disposed in a first filter sub-block for redirecting along the main optical pathway, at least a portion of a first collimated light beam among the N collimated light beams, the first collimated beam of light having the first wavelength; and
a second reflector disposed in a second filter sub-block for redirecting along the main optical pathway at least a portion of a second light beam among the N collimated light beams, the second collimated beam of light having the second wavelength.

3. The optical MUX of claim 1 , wherein N is greater than or equal to four such that the optical MUX comprises at least four light sources, LS 1 -LS 4 , that produce four light beams, LB 1 -LB 4 , and four input optical pathways, IOP 1 -IOP 4 of the filter block for receiving four collimated light beams, CLB 1 -CLB 4 , respectively, from the lens.

4. The optical MUX of claim 1 , wherein the lens has a first side that acts as an exit facet of the lens and a second side that acts as an entrance facet of the lens, and wherein N divergent light beams produced by the N light sources enter the lens via the entrance facet and the N collimated light beams exit the lens via the exit facet, the exit facet of the lens being adjacent a first side of the filter block through which the N collimated light beams enter the filter block and travel along the N parallel input optical pathways, and wherein a refractive index (RI)-matching epoxy is disposed in between the first side of the lens and the first side of the filter block.

5. The optical MUX of claim 4 , wherein at least one of the first side or the second side of the lens is coated with an anti-reflection (AR) coating.

6. The optical MUX of claim 1 , wherein the lens and the filter block are made of a same material.

7. The optical MUX of claim 6 , wherein the lens and the filter block are made of silicon.

8. The optical MUX of claim 6 , wherein the lens and the filter block are made of glass.

9. The optical MUX of claim 6 , wherein the lens and the filter block are made of fused silica.

10. The optical MUX of claim 1 , further comprising:
an output coupler having a first side and a second side, the first side of the output coupler being in contact with a second side of the filter block, wherein a refractive index (RI)-matching epoxy is disposed in between the first side of the output coupler and the second side of the filter block, the output coupler having an input optical port and an output optical port, the input optical port being optically aligned with an output optical pathway of the filter block, the input optical port of the output coupler being interconnected with the output optical port of the output coupler by at least one optical pathway of the output coupler and wherein at least a portion of all of the collimated light beams of all of the WLs that are received in the output coupler via the input optical port of the output coupler are outputted from the output coupler via the output optical port of the output coupler.

11. The optical MUX of claim 10 , wherein at least one of the first side or the second side of the output coupler is coated with an anti-reflection (AR) coating.

12. The optical MUX of claim 10 , wherein the output coupler and the filter block are made of a same material.

13. The optical MUX of claim 12 , wherein the output coupler and the filter block are made of silicon.

14. The optical MUX of claim 12 , wherein the output coupler and the filter block are made of glass.

15. The optical MUX of claim 12 , wherein the output coupler and the filter block are made of fused silica.

16. The optical MUX of claim 1 , wherein the base is a silicon bench, and wherein the silicon bench includes a device holder that extends above the upper surface of the base, and wherein the N light sources are positioned at precise locations on the device holder such that respective optical axes of the N light sources are aligned with respective collimating optical elements formed in the lens.

17. The optical multiplexer of claim 1 , wherein the first wavelength of light is shorter than the second wavelength of light, and the second wavelength of light is shorter than the third wavelength of light.

18. An optical demultiplexer (DeMUX) comprising:
a base having at least an upper surface and a lower surface;
N light detectors mounted on the upper surface of the base, where N is an integer that is greater than or equal to two, each light detector configured to detect a light beam of a particular operating wavelength (WL), and wherein the operating WLs are different from one another; and
a filter block mounted on the upper surface of the base, the filter block arranged to receive a wavelength multiplexed light beam through an input optical port of the filter block and to couple the wavelength multiplexed light beam onto a main optical pathway (OP) that extends between a first end and a second end of the filter block, the main OP orthogonally intersecting N output optical pathways of the filter block, wherein each of the N output optical pathways is oriented towards a respective one of the N light detectors, the filter block including at least a first high pass filter and a second high pass filter, each of which is disposed in the main optical pathway, the first high pass filter configured to pass a first wavelength of light in the wavelength multiplexed light beam while blocking a second wavelength of light in the wavelength multiplexed light beam, the second high pass filter configured to pass each of the first wavelength of light and the second wavelength of light in the wavelength multiplexed light beam while blocking a third wavelength of light in the wavelength multiplexed light beam.

19. The optical DeMUX of claim 18 , wherein the filter block further comprises:
a first reflector dispo

Assignees

• Avago Technologies General Ip

Inventors

• Wang Tak Kui
• Chen Ye
• Yashar Frank

Classifications

• G02B27/1006

  for splitting or combining different wavelengths (G02B27/1086, G02B27/141 take precedence) · CPC title

• G02B27/142 Primary

  Coating structures, e.g. thin films multilayers · CPC title

• G02B6/0001

  specially adapted for lighting devices or systems (lighting or signalling on vehicles using light guides B60Q1/00; lighting devices for vehicle dashboards B60Q3/10; lighting devices for vehicle interior using light guides B60Q3/62; lighting devices mounted on the vehicle rear part using light guides F21S43/235; measuring arrangements having light conducting pointers G01D13/265; illumination of liquid crystal displays G02F1/1336; illuminated signs G09F13/00) · CPC title

• G02B27/30

  Collimators · CPC title

• G02F1/11

  based on acousto-optical elements, e.g. using variable diffraction by sound or like mechanical waves (acousto-optical deflection G02F1/33) · CPC title