Patent ID: 6833917
Filing Date: 2004-12-21
Classification: G01J

Abstract:
A spectrometer for discerning components of collimated light comprising:a P-polarizer for P-polarizing said collimated light; a open-ended hollow capsule having an optically transparent window for receiving said P-polarized light; liquid crystals, said hollow capsule being substantially filled with said liquid crystals for transmitting said P-polarized light as received at said optically transparent window to a boundary surface at said open-ended end of said capsule, said liquid crystals being of a material that is of relatively high light dispersiveness that separates said P-polarized light into wavelength dependent (k-vector) directions representative of different colors wherein said liquid crystals are aligned with respect to said boundary surface to maximize the dispersive effect of said liquid crystals so that Snell component values at said boundary surface are made markedly different for different wavelengths of said P-polarized light, said liquid crystals having a characteristic of varying between an extraordinary refractive index state in which liquid crystal molecules of said liquid crystals have long axes that are substantially normal to said boundary surface and wherein said P-polarized light experiences an extraordinary refractive index of said liquid crystals, and an ordinary refractive index state in which liquid crystal molecules of said liquid crystals have long axes that are substantially parallel to said boundary surface and wherein said P-polarized light experiences an ordinary refractive index of said liquid crystals, said liquid crystals being sandwiched between opposing electrodes wherein said liquid crystals are variable between said extraordinary state and said ordinary state by varying a voltage difference between said opposing electrodes; and an output optically transparent element for receiving said P-polarized light as transmitted through said liquid crystals and presented at said boundary surface and having an output surface for emitting light within a desired passband when present, said output element being of a highly birefringent, relatively low light dispersiveness material having an optic axis other than normal to said boundary surface and aligned to maximize the birefringence affect of said material, said material being characterized by having a plurality of index surfaces corresponding to different colors so that a Snell's component received from said liquid crystals within said passband aligns tangentially with one of said index surfaces to propagate light within said desired passband through said outer surface in the direction of a ray vector that is substantially parallel to said boundary surface.