Polarization-insensitive phase modulator

An optical device, comprising:

• a first polarization-dependent lens, which comprises:
• a first electro-optical layer, which is configured to refract a first polarization component of light propagating along an optical path, with an effective first local index of refraction at any given location that is determined by first control voltage waveforms applied across the first electro-optical layer;
• and
• a first array of excitation electrodes extending across the first electro-optical layer;
• a second polarization-dependent lens, which is arranged in series with the first polarization-dependent lens along the optical path and comprises:
• a second electro-optical layer, which is configured to refract a second polarization component of the light, orthogonal to the first polarization component, with an effective second local index of refraction at any given location that is determined by second control voltage waveforms applied across the second electro-optical layer;
• and
• a second array of excitation electrodes extending across the second electro-optical layer;
• and
• control circuitry, which is coupled to apply the first and second control voltage waveforms respectively to the first and second arrays of the excitation electrodes and is configured to modify the first and second control voltage waveforms so as to generate a specified phase modulation profile in the first and second electro-optical layers.

A method for producing an optical device, the method comprising:

• providing an electro-optical layer, comprising a liquid crystal material with a heliconical structure having a pitch that is less than 250 nm and is modifiable by an electric field;
• positioning an array of excitation electrodes to extend over the electro-optical layer;
• and
• coupling control circuitry to apply control voltage waveforms to the excitation electrodes and to modify the control voltage waveforms so as to locally modify a molecule director angle of the heliconical structure and thus to generate a specified phase modulation profile in the electro-optical layer.

A method for producing an optical device, the method comprising:

• providing a first polarization-dependent lens, comprising:
• a first electro-optical layer, which is configured to refract a first polarization component of light propagating along an optical path, with an effective first local index of refraction at any given location that is determined by first control voltage waveforms applied across the first electro-optical layer;
• and
• a first array of excitation electrodes extending across the first electro-optical layer;
• arranging a second polarization-dependent lens in series with the first polarization-dependent lens along the optical path, wherein the second polarization-dependent lens comprises:
• a second electro-optical layer, which is configured to refract a second polarization component of the light, orthogonal to the first polarization component, with an effective second local index of refraction at any given location that is determined by second control voltage waveforms applied across the second electro-optical layer;
• and
• a second array of excitation electrodes extending across the second electro-optical layer;
• and
• coupling control circuitry to apply the first and second control voltage waveforms respectively to the first and second arrays of the excitation electrodes and to modify the first and second control voltage waveforms so as to generate a specified phase modulation profile in the first and second electro-optical layers.