Abstract: A method and apparatus is provided for attaching an optical fiber to a waveguide formed on a planar lightguide circuit (PLC). The method begins by securing at least one joint element to a first surface of the PLC. The joint element has a beveled surface such that a gap is formed between the joint element and the first surface of the PLC. The gap is adjacent to an end face of the waveguide. The waveguide end face extends in a plane that includes a transverse surface of the joint element to define therewith a first mating surface. The optical fiber is secured to a support member such that an end face of the optical fiber extends in a plane that includes a transverse surface of the support member to define a second mating surface therewith. The waveguide end face is aligned with the optical fiber end face.

Abstract: An erbium doped fiber amplifier includes a wavelength division multiplexer (WDM) which receives a data signal having a first wavelength through a first optical fiber which is single-mode at the first wavelength. Pump light supplied by an energy pump has a second wavelength shorter than the first. The pump light is provided through a second optical fiber which is multi-mode at the pump wavelength. The data signal and the pump light are multiplexed by the WDM. A third optical fiber is coupled to the WDM to receive the multiplexed output. The third fiber is single-mode at the data signal wavelength and multi-mode at the pump wavelength. The third fiber is erbium doped to amplify the input the data signal or is connected to a suitably doped fiber.

Abstract: The present invention is a method for compensating for stress induced in optical components used to couple light egressing from the housing of optical modules employing, for example, a distributed optical isolator. It has been discovered that this induced stress may be counteracted by transmitting a balancing or compensating force so as to produce a counter-stress in the optical component. Preferably, the method uses pairs of circumferential laser welds judiciously formed a distance form the holder housing the optical component so as s to control the magnitude and direction of the applied compensating force and, hence, the counter-stress transmitted to the optical component. During welding, the effects of the induced stress are monitored and based upon any changes therein, pairs of laser welds are formed around the circumferential surface of the housing of the optical component until the induced stress is substantially reduced or eliminated.

Abstract: The invention is a laser assembly for reducing distortion ripple. The assembly includes a spherical lens which has a portion of its surface made optically asymmetric to prevent multiple reflections of scattered light within the lens.

Abstract: The invention is a laser assembly with reduced distortion ripple. The assembly includes a spherical lens for collimating light emitted from the laser. The lens is made of a material which attenuates scattered light which is the source of ripple without appreciably affecting the main beam.

Abstract: An optical coupling arrangement comprises conventional focusing optics and an anamorphic (i.e., radially non-symmetric) lens positioned at the entrance to the optical fiber. The objective lens focuses the elliptical beam exiting a laser source and the anamorphic lens functions to change the beam mode from elliptical to circular. The positioning of the anamorphic lens at the fiber input (instead of the laser output) reduces the alignment tolerance problems associated with prior art arrangements.

Abstract: A system for providing efficient coupling between an elliptical mode laser source and a single mode transmission fiber is disclosed. In one embodiment, the system comprises a cruciform cylindrical lens formed as a pair of perpendicular cylindrical lenses to provide for separate magnification of the "fast" diverging component (i.e., this component passes through a "fast" cylindrical lens) and the "slow" diverging component of the beam (i.e., this component passes through a "slow" cylindrical lens). By decoupling the magnification requirements of the components of the elliptical beam, the beam may be transformed into an essentially circular beam, appropriate for coupling into a single mode fiber. In one arrangement of the present invention, a coupling efficiency of approximately 90% is possible (as compared with prior art coupling efficiency of about 44%).

Abstract: The invention is a circuit for monitoring the wavelength of a laser device such as a semiconductor laser. A piezoelectric resonator is positioned in the path of the light beam so as to form a Fabry-Perot cavity. The changes in the reflectivity of the cavity are detected as the resonator is driven by an oscillator circuit, and an error signal is produced in response thereto when the wavelength of the laser device strays from a desired value.