초록 ▼

Disclosed herein is a light modulating apparatus comprising first and second two periodic structures each having a period smaller than the wavelength of light emitted from a light source, and a moving means for relatively moving the two periodic structures, wherein the surface of the first periodic

Disclosed herein is a light modulating apparatus comprising first and second two periodic structures each having a period smaller than the wavelength of light emitted from a light source, and a moving means for relatively moving the two periodic structures, wherein the surface of the first periodic structure is brought near to the surface of the second periodic structure to a space not longer than the wavelength to arrange them in a state opposed to each other, the light incident on the first periodic structure is converted into near-field light by the first periodic structure, the converted near-field light is transmitted through the second periodic structure and converted into propagation light by scattering the near-field light on the back surface of the second periodic structure, and the intensity of the propagation light is modulated by relatively moving the two periodic structures by the moving means.

대표청구항 ▼

Disclosed herein is a light modulating apparatus comprising first and second two periodic structures each having a period smaller than the wavelength of light emitted from a light source, and a moving means for relatively moving the two periodic structures, wherein the surface of the first periodic

Disclosed herein is a light modulating apparatus comprising first and second two periodic structures each having a period smaller than the wavelength of light emitted from a light source, and a moving means for relatively moving the two periodic structures, wherein the surface of the first periodic structure is brought near to the surface of the second periodic structure to a space not longer than the wavelength to arrange them in a state opposed to each other, the light incident on the first periodic structure is converted into near-field light by the first periodic structure, the converted near-field light is transmitted through the second periodic structure and converted into propagation light by scattering the near-field light on the back surface of the second periodic structure, and the intensity of the propagation light is modulated by relatively moving the two periodic structures by the moving means. m 8, wherein the plasma space includes a reactive gas of Helium. 14. The apparatus as claimed in claim 8, wherein the spectral lines have wavelengths around 438.8*10-9meters. 15. The apparatus as claimed in claim 8, wherein the data processor has a built-in lookup table providing the relationship between the line distance and the gap distance. 16. The apparatus as claimed in claim 8, wherein the chamber is an etch chamber for etching semiconductor wafers. 17. The apparatus as claimed in claim 8, wherein the electrodes comprise a top electrode and a bottom electrode, the plasma space is formed between the top electrode and the bottom electrode, and a semiconductor wafer is disposed above on the bottom electrode. pposite ends thereof, a pair of end electrodes electrically communicating with the upper portions of said chamber adjacent opposite ends and extending toward the central portion of said chamber, and a common electrode electrically communicating with the lower portion of said chamber. 3. The transmitter for projecting a beam of laser light according to claim 2, in which said current sensor includes a test resistance connected to one of said end electrodes, and a test circuit for determining the voltage across said test resistance in response to the application of a test signal of predetermined voltage and short duration across said end electrodes of said level vial. 4. The transmitter for projecting a beam of laser light according to claim 1, in which said temperature sensor includes a circuit for sensing the bulk resistivity of said quantity of electrically conductive fluid. 5. The transmitter for projecting a beam of laser light according to claim 1, in which said projection arrangement for directing the laser light at a selected grade includes an arrangement for changing the direction of said beam until said selected grade is reached, and in which said temperature correction circuit includes a circuit for providing said offset grade value thereto. 6. The transmitter for projecting a beam of laser light according to claim 5, in which said circuit for providing an offset grade value to said arrangement for changing the direction of said beam includes a look-up table having offset grade values associated with specific temperature ranges, said offset grade values being specific to the individual transmitter, whereby temperature induced errors associated with any portion of the transmitter may be compensated. 7. The transmitter for projecting a beam of laser light according to claim 6, in which said look-up table has offset grade values associated with at least three specific temperature ranges. 8. The transmitter for projecting a beam of laser light according to claim 1, in which said temperature sensor further comprises a thermistor. 9. The transmitter for projecting a beam of laser light according to claim 1 in which said source of a beam of laser light is a source of a rotating beam of laser light defining a reference plane, in which said projection arrangement directs the laser light at selected grades in first and second orthogonal axes, and in which said temperature correction circuit includes first and second look-up tables for adjusting said projection arrangement such that temperature induced errors in the direction of said beam of laser light along said first and second axes are compensated. 10. The transmitter for projecting a beam of laser light according to claim 1 in which said projection arrangement for directing the beam of laser light at a selected grade includes a generally conical reflector which reflects said beam radially outward, substantially in a reference plane, in which said projection arrangement directs the laser light at selected grades in first and second orthogonal axes, and in which said temperature correction circuit includes first and second look-up tables for adjusting said projection arrangement such that temperature induced errors in the direction of said beam of laser light along said first and second axes are compensated. 11. A method of calibrating a transmitter for projecting a beam of laser light, said transmitter having a source of laser light, a projection arrangement for directing the laser light at a selected grade, a temperature sensor for detecting the temperature of said transmitter, and a temperature correction circuit, responsive to said temperature sensor, for adjusting said projection arrangement such that temperature induced errors in the direction of said beam of laser light are compensated, and said beam of laser light is thereby directed substantially at said selected grade, comprising the steps of: a.) selecting a plurality of temperature ranges for which correction wi