Abstract: A fiberoptic coupler capable of many functions is presented. The basic fiberoptic coupler has a first sleeve, a second sleeve, a first collimating GRIN or conventional lens, and a second collimating GRIN or conventional lens. The first sleeve holds end sections of two or more input optical fibers along the longitudinal axis of the sleeve. The second sleeve holds an end section of at least one output optical fiber. The end face of the second sleeve faces the first sleeve end face. The first collimating GRIN or conventional lens in front of the first sleeve end face collimates light signals from the input optical fibers and the second collimating GRIN or conventional lens in front of the second sleeve end face focusses light signals from at least one of the input optical fibers into the single output fiber, or at least one of the output optical fibers. With only one output fiber the coupler operates as a combiner.

Abstract: The present invention provides fiber optic couplers for use with at least three optic fibers. The optic fibers arranged in a linear array, that is, the optic fibers are coupled side by side. The fibers along either end of the linear-array are coupled only to a single fiber, while the remaining fibers are generally coupled between only two adjacent fibers. Generally, at least one of the fibers has a propagation constant different that the other fibers. Such variations in the propagation constant are used to vary the coupling coefficients among the fibers of the linear-array, thereby providing a repeatable mechanism, to vary coupled power ratios among the fibers of the coupler. Theoretical calculations and empirical experience have shown that varying the propagation constant of fibers among a linear-array, generally by pre-pulling the fibers by varying amounts, allows repeatable manufacturing of 1.times.3, 1.times.4, 4.thrfore.3, 1.times.N and even N.times.N fiber couplers having even coupled power ratios.

Abstract: A fiberoptic coupler capable of many functions is presented. The basic fiberoptic coupler has a first sleeve, a second sleeve, a first collimating GRIN or conventional lens, and a second collimating GRIN or conventional lens. The first sleeve holds end sections of two or more input optical fibers along the longitudinal axis of the sleeve. The second sleeve holds an end section of at least one output optical fiber. The end face of the second sleeve faces the first sleeve end face. The first collimating GRIN or conventional lens in front of the first sleeve end face collimates light signals from the input optical fibers and the second collimating GRIN or conventional lens in front of the second sleeve end face focusses light signals from at least one of the input optical fibers into the single output fiber, or at least one of the output optical fibers. With only one output fiber the coupler operates as a combiner.

Abstract: A laser diode package assembly is described. Besides a laser diode, the package assembly has an optical fiber section having an end located to receive the light output from the laser diode. The optical fiber section also has a fiber grating designed to operate as a bandpass filter. The fiber grating inside the package assembly not only narrows the output wavelength from the laser diode, but also increases the lifetime of the laser diode.

Abstract: A fiberoptic coupler capable of many functions is presented. The basic fiberoptic coupler has a first sleeve, a second sleeve, a first collimating GRIN or conventional lens, and a second collimating GRIN or conventional lens. The first sleeve holds end sections of two or more input optical fibers along the longitudinal axis of the sleeve. The second sleeve holds an end section of at least one output optical fiber. The end face of the second sleeve faces the first sleeve end face. The first collimating GRIN or conventional lens in front of the first sleeve end face collimates light signals from the input optical fibers and the second collimating GRIN or conventional lens in front of the second sleeve end face focusses light signals from at least one of the input optical fibers into the single output fiber, or at least one of the output optical fibers. With only one output fiber the coupler operates as a combiner.

Abstract: The present invention provides fiber optic couplers for use with at least three optic fibers. The optic fibers arranged in a linear array, that is, the optic fibers are coupled side by side. The fibers along either end of the linear-array are coupled only to a single fiber, while the remaining fibers are generally coupled between only two adjacent fibers. Generally, at least one of the fibers has a propagation constant different than the other fibers. Such variations in the propagation constant are used to vary the coupling coefficients among the fibers of the linear-array, thereby providing a repeatable mechanism, to vary coupled power ratios among the fibers of the coupler. Theoretical calculations and empirical experience have shown that varying the propagation constant of fibers among a linear-array, generally by pre-pulling the fibers by varying amounts, allows repeatable manufacturing of 1.times.3, 3.times.3, 1.times.4, 4.times.4, 1.times.N and even N.times.

Abstract: An improved optical attenuator minimizes polarization mode dispersion in optical signals carried by optical fiber systems. The optical signals are expanded and refocussed by GRIN lenses, and the attenuator makes use of a liquid crystal cell disposed between birefringent polarizers for polarization-independent attenuation or switching. A birefringent plate compensates for dispersion of the ordinary and extra-ordinary rays within the attenuator. The plate will often be disposed at an oblique angle to minimize walk-off between these rays.

Abstract: A laser diode package assembly is described. Besides a laser diode, the package assembly has an optical fiber section having an end located to receive the light output from the laser diode. The optical fiber section also has a fiber grating designed to operate as a bandpass filter. The fiber grating inside the package assembly not only narrows the output wavelength from the laser diode, but also increases the lifetime of the laser diode.

Abstract: A fiberoptic coupler capable of many functions is presented. The basic fiberoptic coupler has a first sleeve, a second sleeve, a first collimating GRIN or conventional lens, and a second collimating GRIN or conventional lens. The first sleeve holds end sections of two or more input optical fibers along the longitudinal axis of the sleeve. The second sleeve holds an end section of at least one output optical fiber. The end face of the second sleeve faces the first sleeve end face. The first collimating GRIN or conventional lens in front of the first sleeve end face collimates light signals from the input optical fibers and the second collimating GRIN or conventional lens in front of the second sleeve end face focusses light signals from at least one of the input optical fibers into the single output fiber, or at least one of the output optical fibers. With only one output fiber the coupler operates as a combiner.

Abstract: A fiberoptic network transmission system combines the output signals of several laser sources into a single optical fiber. The transmission system has integrated optical isolator couplers which each have at least two input optical fibers and an output optical fiber. Each input optical fiber is connected to a laser source and the output optical fiber is connected to an input terminal of a combiner which has its output terminal connected to the single optical fiber. The integrated optical isolator couplers block light from the single optical fiber from reaching any of the laser sources.

Abstract: A fiberoptic coupler capable of many functions is presented. The basic fiberoptic coupler has a first sleeve, a second sleeve, a first collimating GRIN or conventional lens, and a second collimating GRIN or conventional lens. The first sleeve holds end sections of two or more input optical fibers along the longitudinal axis of the sleeve. The second sleeve holds an end section of at least one output optical fiber. The end face of the second sleeve faces the first sleeve end face. The first collimating GRIN or conventional lens in front of the first sleeve end face collimates light signals from the input optical fibers and the second collimating GRIN or conventional lens in front of the second sleeve end face focusses light signals from at least one of the input optical fibers into the single output fiber, or at least one of the output optical fibers. With only one output fiber the coupler operates as a combiner.

Abstract: The present invention provides an improved clip for supporting an end of an optical fiber relative to a mount surface. Typically, a sleeve is disposed over the optical fiber adjacent to its end. The clip comprises a clip body having upper and lower surfaces with a flange disposed adjacent to the lower surface. The flange is affixable to the mount surface, and walls extend from the upper surface of the body to define a channel at which the clip is affixable about the sleeve. Advantageously, when the sleeve is affixed within the channel, the body rigidly couples the sleeve to the flange, thereby avoiding misalignment between the optical fiber and any optical device which is on or supported by the mount surface.

Abstract: The present invention provides for a two-stage optical isolator with reduced polarization mode dispersion. Each stage has two birefringent polarizers separated by a Faraday rotator. The polarizers in each stage are oriented with respect to each other to operate conventionally as an optical isolator for light in a backward direction. However, the polarizers in each stage are oriented with respect to the polarizers in the other stage so that a polarization mode along one direction, say, the ordinary direction, of light in the first stage travelling toward the second stage is aligned along the opposite, extraordinary, direction in the second stage and vice versa. In this manner the component of any polarization travels the same optical distance through the optical isolator to substantially reduce polarization mode dispersion.

Abstract: The present invention provides for a two-stage optical isolator with reduced polarization mode dispersion. Each stage has two birefringent polarizers separated by a Faraday rotator. The polarizers in each stage are oriented with respect to each other to operate conventionally as an optical isolator for light in a backward direction. However, the polarizers in each stage are oriented with respect to the polarizers in the other stage so that a polarization mode along one direction, say, the ordinary direction, of light in the first stage travelling toward the second stage is aligned along the opposite, extraordinary, direction in the second stage and vice versa. In this manner the component of any polarization travels the same optical distance through the optical isolator to substantially reduce polarization mode dispersion.

Abstract: The present invention provides for a compensating element in the form of a birefringent plate in an optical isolator which uses a first GRIN lens to collimate the light signal from an input optical fiber, a first birefringent polarizer wedge, an optical Faraday rotator, a second birefringent polarizer wedge, and a second GRIN lens to recollimate the light signal to an output optical fiber. Polarization mode dispersion through said optical isolator is substantially reduced by arranging the fast optical axis of the plate to be perpendicular to the fast optical axis of the polarizer on the same side of the Faraday rotator as the plate and selecting the thickness of the plate in a predetermined manner. The present invention also allows for minimization of "walk-off", which also contributes to some polarization mode dispersion through the isolator.

Abstract: Wavelength division multiplexed couplers are provided with the ends of input and output optical fibers arranged with respect to GRIN lens so that light from one input fiber is directed toward one output fiber with little crosstalk. An integrated wavelength division multiplexed coupler and isolator device useful for connecting fiberoptic amplifiers to pump lasers is also provided with one version of the WDM coupler. The integrated WDM coupler and isolator device has a tap coupler component created by a planar grating which deflects a small portion of the light through the device toward a photodetector circuit for monitoring purposes. The integrated device also may be combined with a laser diode subassembly can be combined to eliminate a pump laser connection for the fiberoptic amplifier.

Abstract: An optical fiber having an improved input fiber end for an optical isolator. The end of the fiber has a flat end surface substantially perpendicular to the longitudinal axis of the fiber. An optical barrier layer, formed by a layer of chromium and a layer of gold, covers the end surface of the fiber with an aperture exposing the core and covering the cladding of the fiber. Light transmission into the end is substantially reduced to increase the reflection loss of the optical isolator.

Abstract: A torch specifically adapted for the manufacture of optical fiber couplers is provided. The torch has a rod and nozzle of, preferably machinable, ceramic. The rod has an inlet for connection to a gas supply source, an outlet, and a gas channel connecting the inlet to the outlet. The nozzle has an inlet for receiving gas from the rod outlet, and an enlarged outlet connected to the nozzle inlet for discharging gas for ignition. The shapes and dimensions of the parts of the torch can be modified for the specific manufacturing requirements for an optical fiber coupler. During the manufacture of optical fiber couplers, the torch can be maintained in an ignited state so that the fusing of optical fibers can be performed uniformly and reliably.

Abstract: An assembly for tuning a laser by a stepper motor alone is provided. A diffraction grating forming a resonance cavity with an end of the laser is rotated by the stepper motor. A follower arm affixed to the rotatable grating, engages a cam, which is driven by the stepper motor. The cam and follower arm are designed so that there is a linear relationship between the rotation of the stepper motor and that of the grating.