Traveling acoustic waves, in an acoustooptic cell which exhibits an anisotropic diffraction mode, diffract a portion of polychromatic light passing through the cell. The acoustic waves are generated by electro-mechanical transducer means powered by electrical signals having a frequency component for each optical wavelength, and each frequency component can be varied over a bandwidth chosen such that light of optical wavelengths not associated with that frequency component is diffracted with an i...

In an optical wavelength meter, the wavelength of light to be measured, such as that obtained from a CW or pulsed laser, is directed through a tunable grating monochromator, serving as a bandpass filter, for passing light within the selected bandpass and determining, to the lowest degree of resolution, the wavelength of the light to be measured. Thence, the light is directed sequentially through a plurality of Fabry-Perot etalon interferometers of increasing degree of resolution. The interferenc...

An apparatus and method for determining the wavelength of light such as mchromatic radiation from a laser source. The apparatus comprises a Fizeau-type interferometer, photoelectric means for receiving the interference fringe pattern produced in the interferometer, means for determining the spatial period and phase of the fringe pattern, and means for calculating from the spatial period and phase the wavelength of the radiation.

A wavelength reading apparatus for a monochromator comprises a monochromator utilizing a dispersion element for dispersing light in accordance with its wavelengths, a dispersion element driver unit for rotating the dispersion element to effect the tuning wavelength scanning operation of the monochromator and a wavelength counter for adding or subtracting a pulse, which is produced each time when the tuning wavelength of the monochromator changes by a predetermined wavelength increment, depending...

An automatic two wavelength photoelasticimeter comprising, in succession, a light source for emitting light having at least two wavelengths, .lambda..sub.1 and .lambda..sub.2 ; a polarizer rotating at constant speed, an orientable quarter-wave plate of orientation .beta. with respect to a reference axis; a model to be analyzed exhibiting double-refraction and having a fast axis which forms an angle .theta. with respect to the reference axis and which provides a phase shift .phi. (which parameter...

A wavelength selector for use in a laser cavity comprising a diffraction grating mounted at an angle near grazing incidence with respect to the beam travelling away from the excited medium and a reflector which reflects the beam diffracted by the grating back along its incidence path. Wavelength tuning is accomplished by rorating this reflector, while the grating remains fixed. Rotation of the grating provides linewidth variation. FIELD OF THE INVENTION The present invention relates generally to...

An improved bichromatic or polychromatic spectrophotometer comprising means enabling the user to electronically select which wavelength of a preselected pair of wavelengths shall serve as a "sample" wavelength, with the other then serving as a "reference" wavelength.

A light beam is reflected back and forth between a rotating body having a retroreflection corner at opposite ends thereof and a fixed mirror to change the wavelength of the light beam by the Doppler effect.

The invention disclosed is a dual wavelength output laser for use in laser rangefinders. Two different laser active media, e.g. CO.sub.2 and DF, are operated in separate laser cavities arranged in tandem in the same optical resonant cavity, resulting in a co-linear dual wavelength laser output.

A semiconductor laser wherein a wide range of laser emission wavelengths can be obtained by varying the composition of monocrystalline alloys employed as semiconductor material. The semiconductor structure comprises on a monocrystalline indium phosphide substrate of a predetermined conductivity type successive epitaxial layers consisting of a first confinement layer of the same conductivity type, an active layer having the formula (Ga.sub.x Al.sub.1-x).sub.0.47 In.sub.0.53 As where x is within t...