Methods for optical attenuation and switching optical beams
View Patent ↗Low loss, reliable variable optical attenuators and 1×2 switches and polarization insensitive low loss, reliable variable optical attenuators and 1×2 optical switches are described. In one embodiment, a system of the present invention includes a polarization separating sub-system a polarization recombining sub-system and one or more switchable volume diffraction gratings to provide polarization insensitive low loss, reliable variable optical attenuators and 1×2 optical switches.
1. A method for switching one input optical beam to two output beams, the method comprising the steps of:
providing a switchable volume diffraction grating;
providing a static grating having a transparent region;
enabling said switchable volume diffraction grating to diffract, with a predetermined diffraction efficiency, the input optical beam into a diffracted beam and a transmitted beam;
diffracting, with a predetermined diffraction efficiency, the input beam into a diffracted beam and a transmitted beam;
diffracting the diffracted beam utilizing the static grating; and,
transmitting the transmitted beam through said transparent region;
wherein the diffracted beam and the transmitted beam comprise the two output beams.
2. The method of claim 1 wherein enabling said switchable volume diffraction grating to diffract comprises configuring the switchable volume diffraction grating in a desired state.
3. The method of claim 1 wherein enabling said switchable volume diffraction grating to diffract comprises applying a control signal.
4. The method of claim 3 wherein applying a control signal comprises one of an optical signal and an electrical signal.
5. The method of claim 4 wherein one of the optical signal and the electrical signal result in switching times of approximately a microsecond.
6. The method of claim 1 wherein enabling said switchable volume diffraction grating to diffract comprises applying a polarization control.
7. The method of claim 1 further comprising:
using the switchable volume diffraction grating to controllably attenuate the intensity of the diffracted beam.