Optical filter sub-assembly cartridge for use in a receiver optical subassembly (ROSA) housing

1. A multi-channel receiver optical sub-assembly (ROSA) comprising:

an optical sub-assembly cartridge comprising:

a cartridge body including at least first and second sidewalls on opposite sides of the cartridge body and extending along a first major axis from a first end to a second end and forming a cavity by an inner surface therein, the first sidewall having an opening configured to allow light to pass into the cavity;

a first optical filter on the second sidewall configured to receive the light at a first angle of incidence relative to normal and selectively pass unassociated channel wavelengths out of the cavity, and to reflect an associated channel wavelength within the cavity at a second angle;

a mirror disposed within the cavity configured to receive the associated channel wavelength and reflect the associated channel wavelength; and

a second optical filter configured to receive the reflected associated channel wavelength;

a ROSA housing including at least first and second sidewalls on opposite sides of the ROSA housing and extending along a second major axis from a first end to a second end and forming a compartment defined by an inner surface therein, and wherein the first sidewall has at least one optical sub-assembly cartridge receptacle configured to receive the optical sub-assembly cartridge.

2. The ROSA of claim 1 , wherein the first angle of incidence is based on a physical angle of the first optical filter, and wherein the physical angle of the first optical filter is about 15 degrees relative to a line drawn perpendicular to the first major axis.

3. The ROSA of claim 1 , wherein the second optical filter is disposed substantially in parallel length-wise with the first major axis.

4. The ROSA of claim 1 , wherein the mirror is angled at about 30 degrees relative to the first major axis.

5. The ROSA of claim 1 , wherein the first optical filter comprises a transparent material having a thin-film WDM filter disposed thereon.

6. The ROSA of claim 1 , wherein the first optical filter comprises a short-pass filter configured to pass wavelengths greater than the associated channel wavelength, and to reflect channel wavelengths greater than or equal to the associated channel wavelength.

7. The ROSA of claim 1 , wherein the second optical filter comprises a band-pass filter configured to pass a narrow spectrum of channel wavelengths such that substantially only a single channel wavelength is passed out of the cavity by the second optical filter.

8. The ROSA of claim 1 , wherein the mirror reflects the associated channel wavelength substantially perpendicular to the first major axis.

9. The ROSA of claim 1 , wherein the cavity provides a first optical path extending generally along the first major axis from the opening to the first optical filter, a second optical path extending from the first optical filter to the mirror, and a third optical path extending from the mirror to the second optical filter.

10. The ROSA of claim 1 , wherein the ROSA housing includes an optical path that extends substantially along the second major axis, and wherein the ROSA is configured to align the optical path of the ROSA housing with the opening of the cartridge body.

11. The ROSA of claim 1 , wherein the ROSA housing provides at least one sidewall opening configured to receive and fixedly attach to a photodiode package, the at least one sidewall opening aligned with the at least one optical sub-assembly cartridge receptacle such that an optical sub-assembly cartridge disposed therein emits the associated channel wavelength from the second optical filter to a photodiode within the photodiode package.

12. An optical transceiver module comprising:

a transceiver housing;

a multi-channel receiver optical sub-assembly (ROSA) located in the transceiver housing and including a ROSA housing having a plurality of optical sub-assembly cartridge receptacles with respective optical sub-assembly cartridges disposed therein, each optical sub-assembly cartridge comprising:

a cartridge body including a plurality of sidewalls at least partially enclosing a cavity therein, the cavity providing an optical path from a first end to a second end of the cartridge body; and

wherein the cavity includes a first optical filter to receive light via the optical path and reflect an associated channel wavelength towards the cavity and pass unassociated channel wavelengths out of the cavity to an adjacent optical sub-assembly cartridge, and a second optical filter to receive the reflected associated channel wavelength and allow the reflected associated channel wavelength to pass through the second optical filter to a photodiode package;

a multi-channel transmitter optical assembly (TOSA) including at least one TO can laser package located in the transceiver housing for transmitting optical signals at different channel wavelengths.

13. The optical transceiver of claim 12 , wherein the ROSA provides an optical path extending from a first end of the ROSA housing to a second end of the housing, and wherein the optical path of each optical sub-assembly cartridge is aligned with the optical path provided by the ROSA.

14. The optical transceiver of claim 12 , further comprising a mirror disposed in the cavity, and wherein the first optical filter is further configured provide the associated channel wavelength to the second optical filter by way of the mirror.

15. The optical transceiver of claim 12 , wherein the first optical filter comprises a short-pass filter, and wherein the second optical filter comprises a band-pass filter.

16. The optical transceiver of claim 12 , wherein the first optical filter and/or the second optical filter comprises a thin-film filter.

17. The optical transceiver of claim 12 , wherein the transceiver is a Quad Small Form-factor Pluggable (QSFP) transceiver module and the ROSA is configured to receive at four different channel wavelengths at transmission rates of at least about 10 Gbps per channel.

18. An optical sub-assembly cartridge for coupling into an optical subassembly housing, the optical sub-assembly cartridge comprising:

a cartridge body formed by at least first and second sidewalls, the first and second sidewalls defining a cavity therebetween, and wherein the first sidewall includes an opening configured to allow laser light to pass into the cavity;

a first optical filter disposed in the cavity to receive the laser light entering the cavity and reflect an associated channel wavelength towards the cavity; and

a second optical filter disposed in the cavity and configured to receive the reflected associated channel wavelength and allow the reflected associated channel wavelength to pass through the second optical filter.

19. The optical sub-assembly cartridge of claim 18 , wherein the first optical filter selectively passes unassociated channel wavelengths out of the cavity.

20. The optical sub-assembly cartridge of claim 19 , further comprising a mirror disposed within the cavity to receive the associated channel wavelength reflected from the first optical filter and reflect the associated channel wavelength towards the second optical filter.