Spatial light modulator, electronic apparatus including the spatial light modulator, and method of fabricating the spatial light modulator
A spatial light modulator for modulating a phase of incident light and emitting phase-modulated light includes a substrate, a plurality of pixels, and a void block layer. Each pixel of the plurality of pixels includes an upper reflective layer, a lower reflective layer, and a cavity layer disposed between the upper reflective layer and the lower reflective layer and having a refractive index that changes based on an electrical signal. The void block layer includes a plurality of pillars supporting the plurality of pixels and separating the plurality of pixels from the substrate, and void regions formed between the substrate and the plurality of pixels.
1 . A spatial light modulator for modulating a phase of incident light and emitting phase-modulated light, the spatial light modulator comprising:
a substrate;
a plurality of pixels, each pixel of the plurality of pixels comprising:
an upper reflective layer;
a lower reflective layer; and
a cavity layer disposed between the upper reflective layer and the lower reflective layer and having a refractive index that changes based on an electrical signal; and
a void block layer comprising:
a plurality of pillars supporting the plurality of pixels and separating the plurality of pixels from the substrate; and
void regions formed between the substrate and the plurality of pixels.
2 . The spatial light modulator of claim 1 , wherein the void regions are substantially a vacuum.
3 . The spatial light modulator of claim 1 , wherein the void block layer further comprises a support layer apart from the substrate and supporting the plurality of pixels, and
wherein the plurality of pillars are disposed between the substrate and the support layer.
4 . The spatial light modulator of claim 1 , wherein each of the void regions has a thickness of 1 micrometer (μm) to 10 μm.
5 . The spatial light modulator of claim 1 , wherein a gap between the plurality of pillars is 1 micrometer (μm) to 10 μm.
6 . The spatial light modulator of claim 1 , wherein each of the plurality of pillars has a width of 0.1 micrometer (μm) to 1 μm.
7 . The spatial light modulator of claim 1 , further comprising:
a planarization layer disposed between the plurality of pixels and the void block layer.
8 . The spatial light modulator of claim 7 , wherein the void block layer further comprises a support layer apart from the substrate and the plurality of pillars,
wherein the plurality of pillars is arranged between the substrate and the support layer, and
wherein the planarization layer is disposed on the support layer.
9 . The spatial light modulator of claim 7 , wherein the planarization layer and the void block layer comprise a same material.
10 . The spatial light modulator of claim 1 , further comprising:
a trench formed between two adjacent pixels of the plurality of pixels.
11 . The spatial light modulator of claim 10 , wherein the trench passes through the void block layer.
12 . The spatial light modulator of claim 1 , wherein the lower reflective layer comprises at least one of a metal mirror layer or a distributed Bragg reflector.
13 . The spatial light modulator of claim 1 , wherein the upper reflective layer comprises a distributed Bragg reflector.
14 . The spatial light modulator of claim 1 , wherein the upper reflective layer comprises a high contrast grating (HCG) layer.
15 . A method of fabricating a spatial light modulator, the method comprising:
sequentially forming, on a substrate, a void block layer, a lower reflective layer, a cavity layer, and an upper reflective layer,
wherein the forming of the void block layer comprises:
forming a sacrificial layer on the substrate;
forming a plurality of through-holes exposing a surface of the substrate by etching the sacrificial layer;
forming a plurality of pillars by filling the plurality of through-holes with a support material; and
removing the sacrificial layer.
16 . The method of claim 15 , wherein the forming of the void block layer further comprises:
at least partially covering a surface of the sacrificial layer by forming the support material; and
forming, on the surface of the sacrificial layer, a first support material layer supported on the substrate by the plurality of pillars.
17 . The method of claim 16 , wherein the removing of the sacrificial layer comprises:
forming a hole in the first support material layer and removing the sacrificial layer by etching the sacrificial layer through the hole.
18 . The method of claim 17 , wherein the forming of the void block layer further comprises:
forming a second support material layer on the first support material layer; and
forming a support layer supporting the lower reflective layer by forming the first support material layer and the second support material layer.
19 . The method of claim 18 , wherein the first support material layer and the second support material layer comprise a same material.
20 . An electronic apparatus, comprising:
a light source configured to emit light of a wavelength; and
a spatial light modulator configured to modulate a phase of light incident from the light source and emit phase-modulated light,
wherein the spatial light modulator comprises:
a substrate;
a plurality of pixels, each pixel of the plurality of pixels comprising:
an upper reflective layer;
a lower reflective layer; and
a cavity layer disposed between the upper reflective layer and the lower reflective layer and having a refractive index that changes based on an electrical signal; and
a void block layer comprising:
a plurality of pillars supporting the plurality of pixels and separating the plurality of pixels from the substrate; and
void regions formed between the substrate and the plurality of pixels.