This is a restricted class for coherent light generator systems wherein an assembly of electrical, mechanical, and optical components produces an intense, coherent, directional beam of light by stimulating electronic, ionic, or molecular transitions to lower energy levels.
The generators of this system consists of (a) a medium which may be solid, liquid or gaseous, comprising a system of particles, molecules, or atoms; (b) means including a source of energy for setting the particles, molecules, or atoms into an excited energy state; and (c) means to abstract electromagnetic wave energy produced by the relaxation of the system of particles, molecules, or atoms to a lower energy state. The means to abstract electromagnetic wave energy provides for escape from said substance of substantially coherent electromagnetic radiation in the optical or Quasi-optical wavelength range. In general, the wavelength of the emitted radiation lies in the range from the ultraviolet to the far infrared of the electromagnetic spectrum, corresponding to a wavelength range extending from 100 to 2,000,000 angstroms.
The generators of these systems when combined with other diverse systems or devices will be classified with the diverse system or device.
REFERENCES TO OTHER CLASSES
SEE OR SEARCH CLASS
128, Surgery, appropriate subclasses for lasers used in surgery.
204, Chemistry: Electrical and Wave Energy, in particular
157.41, and 157.61 for the use of lasers in a reaction. 219, Electric Heating,
121.6, for lasers use in electric arc heating.
250, Radiant Energy,
423+, for lasers used to generate ions; subclasses 281+ for lasers used in ionic separation systems; and subclass 493.1 for other radiant energy generators.
252, Compositions,
301.16+, 301.36, and 301.4+ for compositions used as the active medium in lasers; and subclasses 372+ for gas compositions used as the active medium in lasers.
257, Active Solid-State Devices (e.g., Transistors, Solid-State Diodes),
13, 79 through 103 and 918, for incoherent light emitting injection luminescent devices, and subclasses 80 through 85 for incoherent semiconductor light emitting sources combined with semiconductor light responsive devices. In general, to avoid excessive duplication of the same patents in both Classes 372 and 257, patents with claims reciting coherent light generators (lasers) are not to be cross-referenced in the aforementioned subclasses in Class 257 unless those patents contain disclosure of a light emitting semiconductor device which is NOT a laser or coherent generator.
356, Optics: Measuring and Testing, appropriate subclasses for lasers used in optical measuring and testing.
359, Optics: Systems (Including Communication) and Elements,
27, for holos:graphic systems having a particular laser source; subclasses 109+ for optical communication systems which may use a laser, subclasses 115+ for optical multiplexing communications systems which utilize lasers, and subclasses 333+ for laser used as amplifiers. Search other subclasses for the lenses, reflectors, etc., used in laser systems.
376, Induced Nuclear Reactions: Processes, Systems, and Elements, 103, and 122 for lasers used for nuclear fusion; and subclass 326 for the combination of a laser and a nuclear reactor.
385, Optical Waveguides,
14, for laser in integrated optical circuit.
438, Semiconductor Device Manufacturing: Process,
22+, for methods of making radiation emissive devices of the semiconductor barrier layer type.
150+, for high temperature (Tc 30 K) superconducting devices, particularly subclass 180 for laser generators using high temperature superconducting material.
520, Synthetic Resins or Natural Rubbers.
522, Synthetic Resins or Natural Rubbers,
2, for the use of a laser in preparing or treating a synthetic resin or natural rubber.
708, Electrical Computers: Arithmetic Processing and Calculating, 191, and 800+ for computations which include electro-optic means.
GLOSSARY:
ACOUSTO-OPTIC
The effect, on the properties of a beam of light, by sound energy, interacting with the light within a volume of matter.
ACTIVE MEDIA
The material, in which most of the atoms can be placed in an excited state (i.e., population inversion state), so that an electromagnetic wave of the proper frequency passing through it can stimulate a cascade of photons.
BIREFRINGENT
The property of dividing a ray of light into two polarized rays (known as the ordinary and extraordinary rays), the directions of polarization of the rays being at right angles to each other.
COHERENT LIGHT
A single frequency of light. A light beam in which the electric vector at any point in it is related to that at any other point by a definite, continuous sinusoidal function.
DIFFRACTION The bending of a light ray in passing the edge formed by contiguous opaque and transparent areas.
ELECTRO-OPTIC
The effect, on the properties of a beam of light, by an electrical field, interacting with the light within a volume of matter.
GLOW DISCHARGE
A type of discharge in which a uniform glow is created through the entire volume of a gaseous active media rather than a channel or spark discharge through a restricted portion of the active media.
INTERFERENCE
The interaction of two light waves which, as a result of their relative phases, produce a cancellation or reinforcement of wave energy.
LASER
A device for generating a very narrow, intense beam of coherent light. The name is derived from the initial letters of "Light Amplification by Stimulated Emission of Radiation". In the emission of ordinary light the molecules or atoms of the source emit their radiation independently of each other, and consequently there is no definite phase relationship among the vibrations in the resultant beam. The light is incoherent. The laser, by means of an optical resonator, forces the atoms of the material within the resonator to radiate in phase. The emitted radiation is stimulated by the excitation of atoms to a higher energy level by means of energy supplied to the device.
LIGHT
In this class, light includes not only optical wavelengths, i.e., that part of the spectrum extending from the near infrared, through the visible, to the ultraviolet, but also includes those portions of the spectrum which extends from the near infrared through the long wavelength, far infrared, and from the ultraviolet to X-rays and gamma rays at the shortest wavelengths.
LIGHT, VISIBLE LIGHT Visible light is radiation which stimulates the optical receptors of the eye, and having a wavelength from 3850 to 7600 Angstrom units. The term light is used to refer to wavelengths in the above-mentioned range and, often, also to refer to the ranges immediately adjacent, i.e., the
ultraviolet and infrared ranges which are nonvisible.
MODE
One of several states of electromagnetic wave oscillation that may be sustained in a given resonant system. Each type of vibration is designated as a particular mode, and has its own particular frequency and electric and magnetic field configurations.
OPTICS, OPTICAL
The science of light and vision and the construction of optical instruments.
OPTICAL ELEMENT
A structure which performs a basic optical function, i.e., the structure when exposed to or placed in the path of a group of light rays will cause a deviation of the rays in accordance with a regular pattern, a blocking of the rays, or a modification in the character or properties of the light.
OPTICAL FIBER
A light guidance system that is cylindrical in shape. The fiber relies upon modal transmission to transmit light along its axial length. Light enters one end of the fiber and emerges from the opposite end with only minimal loss.
OPTICAL SYSTEM
A combination of two or more similar or diverse optical elements which are optically related. REFLECTION
Light striking a surface and returning back into the medium from which it came.
REFRACTION
The deviation of light which results when a ray of light passes obliquely from a medium of one density to a medium of another density.
RESONANT CAVITY
A mode-selecting low-loss optical structure in which the laser action takes place by the build-up of electromagnetic field intensity upon multiple reflection.
SEMICONDUCTOR
An electronic conductor, with resistivity between that of metals and that of insulators, in which the electrical charge carrier concentration increases with increasing temperature
over some temperature range. Over most of the practical temperature range, the resistance has a negative temperature coefficient. Certain semiconductors possess two types of carriers, negative electrons and positive holes. The charge carriers are usually electrons, but there may be also some ionic conductivity.
SEMICONDUCTOR LASER
A light-emitting diode that uses stimulated emission to produce a coherent light output.
SPECTRUM The band of colors produced by separating a beam of white light into its component frequencies.
THIN FILM
A film of optically transparent material, usually deposited by sputtering or evaporation, that may be made in a pattern on a substrate or used as insulation between successive layers of components, and generally on the order of a few wavelengths thick.
THIN FILM WAVEGUIDE
A thin dielectric guide film of high refractive index formed adjacent to a substrate or support region of lower refractive index. The thin film relies upon modal transmission to transmit light along its length. Light enters one end of the thin film where it is processed (e.g., modulated or switched) and emerges from the opposite end.
WAVEGUIDE
A system of material boundaries capable of guiding electromagnetic wave. A transmission line comprising a hollow conducting tube within which electromagnetic waves are propagated on a solid dielectric or dielectric-filled conductor.