May 2006Conoptics Inc.Request Info
Prevents Beam LossDANBURY, Conn., May 4, 2006 -- Conoptics has added the 715 I polarizer to its 700 Series Faraday rotators and accessories.
said if a source laser is unpolarized or randomly polarized,
conventional polarizers such as its model 720 cause a time-averaged
50-percent loss to the forward beam. The 721 avoids this loss by
splitting the incident beam into two orthogonal linear components using
double refraction in a birefringent crystal (calcite). A Faraday
rotator and model 730 compensator are oriented so 45-degree rotations
cancel in the forward direction. A second 721 recombines the beams that
proceed from the assembly. The model 730 is required to properly orient
the polarization of the separated beams with respect to the
displacement plane of the output 721.
In the backward direction,
the first 721 encountered performs in its normal beam splitting
function, Conoptics said. The 45-degree rotations of the 730 and
Faraday rotator add, thereby reversing, the polarization of the two
beams as compared to that in the forward direction. The second 721
encountered further spreads the beams, rather than recombining them.
Since the returned power is absorbed by aperture stops that are part of
the assembly, strong reflections of high power sources for more than
brief durations will result in heating. In special situations where
persistent strong reflections cannot be avoided, a modification to the
721 which extracts rather than absorbs the backward flowing power is
In order to transmit in the forward direction and
block in the backward direction, the length of the birefringent element
in the model 721 must be sufficient to spatially resolve the two beams,
the company said. Since the beams travel laterally separated in the
rotator and compensator, the effective clear aperture of polarization
insensitive assemblies incorporating 721s must be reduced to 1.75 mm
and offset 1 mm from the mechanical centerline.For more information, visit: www.conoptics.com; e-mail: email@example.com
19 Eagle Rd.
Danbury, CT 06810