Spatial light modulator using phase-change materials with improved fill factor

1. A method of providing a spatial light modulator comprising:

providing a substrate; and

providing a first phase change material cell on the substrate, the first phase change material cell comprising:

a first electrical heater on the substrate;

a first optical reflector layer on the first electrical heater; and

a first phase change material layer on the first optical reflector layer;

providing at least a second phase change material cell on the substrate, the second phase change material cell comprising:

a second electrical heater on the substrate;

a second optical reflector layer on the second electrical heater;

a second phase change material layer on the second optical reflector layer; and

providing a light absorber layer between the first phase change material cell and the second phase change material cell.

2. The method of claim 1 further comprising:

depositing the first phase change material layer on the first optical reflector layer at room temperature by sputtering;

wherein the phase change material layer comprises a SbTe alloy, or a Ge or an In doped SbTe alloy.

3. The method of claim 1 further comprising:

providing an anti-reflection coating on the first phase change material layer.

4. The method of claim 1 further comprising:

providing a thermal barrier between the first electrical heater and the substrate;

wherein the thermal barrier comprises a dielectric or SiO2.

5. The method of claim 1 wherein the first optical reflector layer is metallic.

6. The method of claim 1 :

wherein when the first phase change material layer is in an amorphous phase, light may be transmitted through the first phase change material layer; and

wherein when the first phase change material layer is in a crystalline phase, light is absorbed and not transmitted through the first phase change material layer.

7. The method of claim 1 wherein the first electrical heater comprises TiW, and is a single zone heater or a dual zone heater.

8. A method of providing a spatial light modulator comprising:

providing a substrate; and

providing a phase change material cell on the substrate, the phase change material cell comprising:

an electrical heater on the substrate;

an optical reflector layer on the electrical heater; and

a phase change material layer on the optical reflector layer;

wherein when the phase change material layer is in an amorphous phase, an optical extinction coefficient is substantially zero for wavelengths ranging from 1 to 17 micrometers; and

wherein when the phase change material layer is in a crystalline phase, the optical extinction coefficient is substantially greater than one for wavelengths ranging from 1 to 17 micrometers.

9. A method of providing a spatial light modulator comprising:

providing a substrate; and

providing a phase change material cell on the substrate, the phase change material cell comprising:

an electrical heater on the substrate;

an optical reflector layer on the electrical heater; and

a phase change material layer on the optical reflector layer;

wherein the electrical heater comprises one of:

a single zone heater comprising:

a first electrode and a second electrode coupled to the electrical heater; and

a heater controller coupled to the first electrode and the second electrode; and

a dual zone heater comprising:

a first electrode and a second electrode coupled to the electrical heater;

a second electrical heater;

a third electrode and a fourth electrode coupled to the second electrical heater; and

a heater controller coupled to the first, second, third and fourth electrodes.