Structure for an optical switch on a substrate

DETAILED DESCRIPTION FIG.
1 shows an embodiment of optical cross-connect system 100 in accordance with the invention.
Two dimensional array 104 of MEMS tilt mirrors 106 is used to direct light beam 101 coming from two dimensional array 108 of optical fibers 110 to two dimensional array 112 of optical fibers 111.
Each mirror 106 can rotate about two non-colinear axes in general.
A typical diameter for mirror 106 is in the range of 300 .
mu.
m to 1000 .
mu.
m.
For example, light beam 101 emerging from optical fiber 110 is collimated using lenslet 115 typically having a diameter greater than about 50 .
mu.
m and projected onto tilt mirror 106 which directs light beam 101 onto lenslet 116 which focuses light beam 101 into optical fiber 111.
Hence, using optical cross-connect system 100, light beam 101 coming from any one of optical fibers 110 in two dimensional array 108 may be directed by one of mirrors 106 of two dimensional array 104 into selected optical fiber 111 of two dimensional optical fiber array 112.
Note that the number of tilt mirrors 106 is equal to the number of optical fibers 110 coming in which in turn is equal to the number of optical fibers 111 going out for optical cross-connect system 100.
Light beam 101 in FIG.
1 generally does not enter optical fibers 111 head-on and this may lead to aperture issues for optical fibers 111, especially for larger optical fiber arrays or shorter optical paths resulting in larger scan angles.
FIG.
2a shows optical cross-connect system 125 in accordance with the invention.
Optical cross-connect system 125 allows optical fibers 111 to be entered head-on by light beam 101.
Optical cross-connect system 125 introduces two dimensional array 105 of tilt mirrors 107 to assure that light beam 101 enters optical fiber 111 head-on.
Light beam 101 originating from optical fiber 110 first strikes tilt mirror 106 and is reflected onto tilt mirror 107 which reflects light beam 101 head-on to optical fiber 111.
However, optical cross-connect system 125 requires double the number of tilt mirrors that is required using optical cross-connect system 100