Infrared radiation modulator
First Claim
1. An infrared radiation modulator comprising three parallely arranged interferometer plates made of a material having a limited absorption rate in the wavelength region of the radiation to be modulated, said interferometer plates forming two successive interferometric slits therebetween for passing the radiation to be modulated, the two outer plates of said three interferometer plates being stationary, and the central plate being suspended to a flexural resonator such that the width of said slits is periodically varied, the interferometer plates being comprised of monocrystalline doped cadmium telluride (CdTe) having a high resistivity and a limited absorption rate for infrared radiation.
0 Assignments
0 Petitions
Accused Products
Abstract
An infrared radiation modulator comprising three parallely arranged interferometer plates, forming two successive slits or cavities therebetween for passing the infrared radiation to be modulated. The width of said slits is periodically varied by the oscillations of the central interferometer plate while the two outer plates remain stationary, a positive variation of the width of one of the slits corresponding at any time to a negative variation of the width of the other slit. A particularly suitable material for the interferometer plates is monocrystalline doped cadmium telluride having a high resistivity and a limited absorption rate for infrared radiation. A very precise alignment of the interferometer plates and an accurate adjustment of the width of the slits therebetween can be achieved by using a wedge-arrangement comprising three radially displaceable wedges disposed at angles of 120° for adjusting the parallelism of the plates and the width of the slits formed between the central plate and the two outer plates when in their normal (rest) position, said adjustment being made independently for each slit. In a particular embodiment, the interferometer plates are made of a material having a high resistance and having marginal zones overlaid with metal layers forming in each slit three uniformly distributed capacitors. By varying the capacitance of said capacitors the width of the interferometric slits or the parallelism of the plates can be adjusted.
-
Citations
13 Claims
- 1. An infrared radiation modulator comprising three parallely arranged interferometer plates made of a material having a limited absorption rate in the wavelength region of the radiation to be modulated, said interferometer plates forming two successive interferometric slits therebetween for passing the radiation to be modulated, the two outer plates of said three interferometer plates being stationary, and the central plate being suspended to a flexural resonator such that the width of said slits is periodically varied, the interferometer plates being comprised of monocrystalline doped cadmium telluride (CdTe) having a high resistivity and a limited absorption rate for infrared radiation.
- 7. An infrared radiation modulator comprising a frame, three parallely arranged inteferometer plates made of a material having a limited absorption rate in the wave-length region of the radiation to be modulated, said interferometer plates forming therebetween two successive interferometric gaps adapted for passing the radiation to be modulated, the two outer plates of said three interferometer plates being fixedly connected to the frame, the central plate being connected to the frame through a flexural resonant vibrator having a resonance frequency, and driving means to cause said resonant vibrator to vibrate at resonance frequency, thereby to cause the gaps to be periodically varied at said resonance frequency.
Specification