By introducing an asymmetry in the effective refractive index profile of a waveguide, wave energy can be extracted from the waveguide by radiation at wavelengths greater than a critical wavelength, where the latter is a function of the effective index distribution. This technique is employed to develop a variety of optical wavelength filters.

Polychromatic beams are separated into component colors or wavelength bands by wavelength selective filters combined with a beamsplitter. These filters are arranged on three sides of a cubic space, with a beamsplitter on the diagonal. The space may be air or a cube of transparent material, such as glass. If the beam is to be split into more than three colors, a second cube is used with additional beamsplitters. At least one filter which receives a beam split by the beamsplitter, either the filte...

An apparatus and method of manufacturing a wavelength converter of an optical fiber type, having a core and a clad covering the core. At least one of the core and clad is made of a nonlinear optical material such that copious amounts of second harmonic light are emitted form a light emitting end face of the optical fiber. Grooves and/or flanges are formed in or on the clad or a transparent layer covering the clad. The transparent layer also covers the light emitting end face of the optical fiber...

In a wavelength converter, nonlinear medium layers containing material having an increased second order susceptibility, and linear medium layers, not containing material having a nonlinear optical characteristic of the second degree, are alternatively layered. A fundamental wave (of which the angular frequency is .omega.) is incident on the multi-layered structure in a direction normal to the major surfaces of the nonlinear medium layers and the linear medium layers, thereby generating the secon...

An optical source emits a source optical signal having a source optical signal power and a wavelength. A splitter or other similar device splits the source optical signal into a first optical signal having a first optical signal power and into a second optical signal having a second optical signal power such that the source optical signal power is split between the first optical signal power and the second optical signal power. This split is dependent upon the wavelength of the source optical si...

The invention relates to a wavelength converter for converting a first light signal used for data transmission and having a first wavelength (.lambda..sub.in) into a second light signal having a second wavelength (.lambda..sub.out). The wavelength converter signal comprises a signal input for picking up the first light signal, a signal output for emitting the second light signal, a modulatable optical semiconductor amplifier (4) with an input, an output and modulation input and a first laser lig...

In an optical wavelength standard, a concrete matrix embeds wavelength reference material. The concrete matrix is formed from a powdered halogenated polymer (e.g., PTFE) which is mixed with powdered wavelength reference materials, such as rare earth oxides, and the mixture is subjected to sufficient pressure to cause the particles of the halogenated polymer to coalesce into the concrete matrix.

Constant wavelength magnetic imaging is provided by generating a signal having a frequency proportional to the speed of a rotational recording member, multiplying that frequency up to a higher, desired recording frequency, and phase-locking the higher frequency signal to the unmultiplied lower frequency, thus synchronizing the recording frequency with the motor speed.

A broadband optical discriminator for determining the wavelength of received radiation which is in a narrow band is described. The received radiation is passed through a polarization spoiler, a linear polarizer, a polarization dispersion device, and a beam splitting polarizer forming two beams. The intensity of the two beams is converted into electrical signals. The electrical signals are processed to provide a signal indicative of the wavelength of the incident radiation.

A multiplexer/demultiplexer for optical fibers is disclosed that features a reflection diffraction grating and a graded refractive index rod in a rugged, compact assembly having low insertion loss and low crosstalk.