Patent ID: 7321542

Claim:
A beam shaping prism, comprising: a first prism having an incident surface; and a second prism having an inclined surface, wherein when an angle that the incident surface makes with an incident beam having an incident angle of θ 1 is α 1 and an angle that the inclined surface makes with a beam that passes from the first prism into the second prism and is reflected from the inclined surface is α 2 , the beam shaping prism satisfies a first equation and allows the beam to emerge perpendicularly to the incident beam: θ ⁢ ⁢ 1 = incident ⁢ ⁢ angle θ2 = sin - 1 ⁡ ( sin ⁢ ⁢ θ1 n1 ) θ3 = θ1 - θ2 θ4 = sin - 1 ⁡ ( n1 × sin ⁢ ⁢ θ3 n2 ) θ5 = 90 ⁢ ° + θ4 2 α1 = 90 ⁢ ° - θ1 α2 = θ5 - θ4 = 90 ⁢ ° - θ4 2 where n 1 and n 2 are refractive indices of the first and second prisms, respectively, θ 2 is a refraction angle of a first beam that is refracted through the incident surface of the first prism, θ 3 is an incident angle of a second beam that passes from the first prism into the second prism, θ 4 is a refraction angle of a third beam refracted through the first prism into the second prism, and θ 5 is an angle that the third beam traveling through the second prism is incident on the inclined surface of the second prism.