Optical switch, image display device, image forming device, and method for manufacturing optical switch

A method for manufacturing an optical switch,

• the optical switch including an electro-optic crystal, and an electrode unit having a plurality of electrodes arranged on the same plane in the electro-optic crystal to extend in parallel to one another, a refractive index of a part of the electro-optic crystal being changed by an electric field generated at the electrode unit, thereby switching transmission and reflection of light incident on the electro-optic crystal,
• the method comprising the step of:
• forming the plurality of electrodes on the same plane of the electro-optic crystal at an inclination by setting an angle θx formed between an end surface of the electro-optic crystal and a longitudinal direction of the electrodes near an angle that satisfies the following expression (1):
• θx=90°−Sin−1[ cos(Tan−1(n))] (1)
• (n denotes a refractive index of the electro-optic crystal in a wavelength of light to be modulated).

A method for manufacturing an optical switch,

• the optical switch including an electro-optic crystal, and an electrode unit having a plurality of electrodes arranged on the same plane in the electro-optic crystal to extend in parallel to one another, a refractive index of a part of the electro-optic crystal being changed by an electric field generated at the electrode unit, thereby switching transmission and reflection of light incident on the electro-optic crystal,
• the method comprising the steps of:
• forming the plurality of electrodes on the same plane of the electro-optic crystal by setting a longitudinal direction of the electrodes orthogonal to an end surface of the electro-optic crystal;
• and
• cutting the electro-optic crystal having the plurality of electrodes along a cut surface,
• wherein in the cutting step, an angle θx of the cut surface to the longitudinal direction of the electrodes is set near an angle that satisfies the following expression (1):
• θx=90°−Sin−1[ cos(Tan−1(n))] (1)
• (n denotes a refractive index of the electro-optic crystal in a wavelength of light to be modulated).