Broadband optics for manipulating light beams and images
Pointing and positioning system of light beams and images including a plurality of cycloidal diffractive waveplates, each waveplate capable of deviating a generally broadband light beam over a predetermined angle. The lateral translation and deviation angles of the light beams are controlled by controlling the relative distance, rotational position, and the diffractive efficiency of a least one in the plurality of waveplates.
1. A system for positioning light beams comprising:
(a) a set of two cycloidal diffractive waveplates that are bonded with each other, with or without spacers, one of said cycloidal diffractive waveplates having variable diffraction spectrum, with electrodes deposited on one substrate of a liquid crystal cell with cycloidal orientation of a liquid crystal in the liquid crystal cell, and another one of the cycloidal diffractive waveplates being not stimuli responsive to an electric field;
(b) means for controlling the diffraction spectrum of said variable cycloidal diffractive waveplate between diffractive and non-diffractive states, by applying an electric field through the electrodes to align liquid crystal molecules along the electric field and transform spatially modulated liquid crystal orientation into a homogenous orientation; and
(c) a light source for generating a light beam into the set of two cycloidal diffractive waveplates, wherein the system controls pointing and positioning the beam.
2. The system of claim 1 further comprising an optical setup for receiving and controlling light at an output of said cycloidal diffractive waveplates, said optical setup including one or a combination of the following: spatial filters, spectral filters, polarizers, diffraction gratings.
3. The system of claim 1 , wherein the electric field includes a sinusoidal electric field of around 1 kHz frequency.
4. The system of claim 3 , wherein the electric field is 1 V to 100 V.
5. The system of claim 1 , wherein the one cycloidal diffractive waveplate with the variable diffraction spectrum is deposited on a single support substrate and serves as a basis for the another cycloidal diffractive waveplate.
6. The system of claim 1 , wherein the cycloidal diffractive waveplates are separated from one another by a spacer layer, the spacer layer includes a liquid crystal with electrodes sandwiched between glass substrates.
7. The system of claim 1 , further comprising:
a second set of two cycloidal diffractive waveplates that are bonded with each other, with or without spacers, one of said cycloidal diffractive waveplates having variable diffraction spectrum, with electrodes deposited on one substrate of a liquid crystal cell with cycloidal orientation of a liquid crystal in the liquid crystal cell, and another one of the cycloidal diffractive waveplates being not stimuli responsive to an electric field; and
means for controlling the diffraction spectrum of said variable cycloidal diffractive waveplate between diffractive and non-diffractive states, by applying an electric field through the electrodes to align liquid crystal molecules along the electric field and transform spatially modulated liquid crystal orientation into a homogenous orientation.