Optical system

An optical system comprising:

• a first light source configured to emit light having a first wavelength;
• a second light source configured to emit light having a second wavelength different from the first wavelength;
• a first spatial optical phase modulator configured to output first phase-modulated light which is based on input light having the first wavelength emitted from the first light source;
• a second spatial optical phase modulator configured to output second phase-modulated light which is based on input light having the second wavelength emitted from the second light source;
• and
• a projector configured to project the first phase-modulated light and the second phase-modulated light on a target,
• wherein the first spatial optical phase modulator is a liquid crystal device that includes a first liquid crystal layer for generating the first phase-modulated light from the input light having the first wavelength,
• wherein the second spatial optical phase modulator is a liquid crystal device that includes a second liquid crystal layer for generating the second phase-modulated light from the input light having the second wavelength,
• wherein the first liquid crystal layer includes a liquid crystal material that is different from a liquid crystal material included in the second liquid crystal layer,
• wherein the first wavelength is longer than the second wavelength,
• wherein the second wavelength is a blue wavelength,
• wherein the second liquid crystal layer includes a liquid crystal material that has higher light durability than the first liquid crystal layer, the liquid crystal material including, as an additive, a polymerization inhibitor for inhibiting a polymerization reaction caused by a light action, and
• wherein the first liquid crystal layer includes a liquid crystal material that has a higher birefringence than the second liquid crystal layer, the liquid crystal material of the first liquid crystal layer including the polymerization inhibitor in a smaller amount than the second liquid crystal layer,
• wherein the first liquid crystal layer includes a liquid crystal material that includes a liquid crystal compound having a tolan structure,
• wherein the second liquid crystal layer includes a liquid crystal material that includes no liquid crystal compound having a tolan structure,
• wherein the first liquid crystal layer and the second liquid crystal layer each have a thickness, and
• wherein the first spatial optical phase modulator and the second spatial optical phase modulator each have a maximum phase modulation amount of 2π or greater, depending on the thickness of the first liquid crystal layer and the thickness of the second liquid crystal layer, respectively.