Free space optical (fso) system

Abstract

A detector configuration for use in a free space optical (FSO) node for transmitting and/or receiving optical signals has a plurality of sensors for detecting received optical signals. The plurality of sensors is configured along a common optical path and are used for separate functions. According, the detectors may be optimized for the respective function.

The invention claimed is: 
     
         1 . A free space optical terminal, comprising:
 a wave front sensor comprising a free space in an interior region of the wave front sensor;   a receiver concentric with the free space of the wave front sensor.   
     
     
         2 . The free space optical terminal of  claim 1 , wherein the receiver comprises an optical fiber. 
     
     
         3 . The free space optical terminal of  claim 2 , wherein the optical fiber is a bi-directional fiber. 
     
     
         4 . The free space optical terminal of  claim 2 , wherein the optical fiber is a uni-directional fiber. 
     
     
         5 . The free space optical terminal of  claim 1 , wherein the wave front sensor is a plurality of sensors circumscribing a perimeter of the receiver as seen from a front view normal to a receiving surface of the receiver. 
     
     
         6 . The free space optical terminal of  claim 5 , wherein the plurality of sensors substantially completes a perimeter around the receiver as seen from the front view. 
     
     
         7 . The free space optical terminal of  claim 6 , wherein the plurality of sensors approximately completely completes the perimeter around the receiver as seen from the front view. 
     
     
         8 . The free space optical terminal of  claim 5 , wherein a terminal surface of the optical fiber is positioned in plane with a working surface of the plurality of sensors as oriented with respect to an incoming received beam. 
     
     
         9 . The free space optical terminal of  claim 5 , wherein the plurality of sensors comprises a quadcell. 
     
     
         10 . The free space optical terminal of  claim 9 , wherein the free space is defined by a hole in the center of the quadcell. 
     
     
         11 . A free space optical (FSO) terminal, comprising: a wave front sensor used for aligning the system and a detector used to receive a data transmission received on an optical beam, wherein the wave front sensor and the detector are different optical components, the system being configured such that a first portion of the received light is received at the wave front sensor and a second portion of the received light source is received at the detector, where a beam splitter is not used to separate the first portion from the second portion. 
     
     
         12 . The free space optical terminal of  claim 11 , wherein the FSO terminal is configured to transmit and receive with common optics. 
     
     
         13 . The free space optical terminal of  claim 11 , wherein the first portion and second portion follow the same optical beam path along an entire length within the system. 
     
     
         14 . The free space optical terminal of  claim 12 , wherein the first portion circumscribes the second portion.