US 11,722,236 B1
Polarization-maintaining wavelength selective switch for free-space optical communication
Ian G. Clarke, Sydney (AU); and Massimo Di Blasio, Princeton, NJ (US)
Assigned to II-VI DELAWARE, INC., Wilmington, DE (US)
Filed by II-VI Delaware, Inc., Wilmington, DE (US)
Filed on Apr. 5, 2022, as Appl. No. 17/658,053.
Int. Cl. H04J 14/02 (2006.01); H04B 10/11 (2013.01); H04B 10/2507 (2013.01)
CPC H04J 14/0212 (2013.01) [H04B 10/11 (2013.01); H04B 10/2507 (2013.01)] 22 Claims
OG exemplary drawing
 
1. A module for free-space optical communication using optical signals, the optical signals having wavelength division multiplexed (WDM) channels, each of the WDM channels having polarization states, the module comprising:
a polarization conversion assembly being configured to convert circular polarization states of incoming ones of the optical signals from the free-space optical communication to linear polarization states and being configured to convert linear polarization states to circular polarization states for outgoing ones of the optical signals of the free-space optical communication;
a fiber array arranged in optical communication with the polarization conversion assembly and having polarization-maintaining optical fibers for the optical signals, each of the polarization-maintaining optical fibers being configured to preserve the linear polarization states; and
a wavelength selective switch arranged in optical communication with the fiber array and having free-space optics with optical axes, the wavelength selective switch being configured to selectively switch the WDM channels of the optical signals relative to the polarization-maintaining optical fibers, wherein fast and slow axes of the polarization-maintaining optical fibers of the fiber array are aligned to the optical axes of the free-space optics.