Abstract: There is disclosed a high speed pulse train generator for generating a train of pulses having arbitrarily close spacing. The apparatus consists of a generator loop comprised of a fiber optic waveguide looped through a directional coupler with the output fiber serving as the input fiber for a similarly structured multiplexer loop. The lengths of the two loops are adjusted such that the time difference in the propagation times of light around the respective loops is small compared to the time of propagation around either loop. The times are adjusted to obtain any arbitrary spacing of the pulses in the output pulse train which is comprised of interleaved pulse trains resulting from each pulse input to the multiplexer loop. Also disclosed is a single loop embodiment for bidirectional data rate transformation and methods of using all the embodiments.

Abstract: Apparatus for accurately and automatically aligning a pair of optical fibers in abutting end-to-end relationship. The apparatus includes an optical fiber holder having an opening in substantially the exact center of one end thereof for supporting the end of an optical fiber therein. The holder comprises a one-piece, cylindrical-shaped housing having integral centering elements around the periphery thereof. The centering elements cooperate with the wall of a bore in a connector member within which the holder is adapted to be inserted to automatically center the housing within the bore, and hence, to automatically align the end of the optical fiber with the bore axis.When a second, similarly constructed holder supporting the end of a second optical fiber is also inserted into the bore of the connector member with their respective one ends in abutting end-to-end relationship, the ends of the two optical fibers will automatically be aligned with the bore axis and, hence, with each other.

Abstract: A method for alignment of optical fiber connector halves, including the steps of securing a connector lens in a lens holder having a planar end face, forming a reference plane parallel to or coplanar with the planar face of the lens holder, and then positioning an optical fiber such that, if the reference plane is reflective, light launched into the lens from the fiber will be maximally reflected back into the fiber. In one disclosed embodiment of the invention, the lens holder planar surface and an end surface of the lens are ground and polished together to form a common reference plane. Three alternative approaches are disclosed for detecting light reflected back into the fiber. The first approach detects light in the fiber core by means of a beam-splitting mirror. The second approach relies on the detection of light in the fiber cladding material, which is minimized when the fiber is properly aligned with the lens.

Abstract: An optical coupling device for diverting light among different transmission elements. The device includes at least one graded-index-of-refraction lens with transmission elements coupled to one surface. At the opposite surface of the lens is a reflecting element which is adapted for movement so as to vary the angle of reflection of the incoming light from one of the transmission elements.

Abstract: An inline single-mode fiber attenuator (10) is disclosed which may be formed by a tandem combination of a birefringent polarization-preserving fiber (12) and a single polarization fiber (14). The birefringent fiber functions as a variable wave plate and the single polarization fiber functions as a fiber polarizer. By continuously changing the local birefringence of the birefringent fiber with, for example, tension, pressure, or temperature, the phase difference between the two polarization components of light traveling through the birefringent fiber is continuously modified. The difference in phase causes suppression of one of the polarization components as it enters the fiber polarizer and, therefore, the output of the fiber polarizer, the sum of the two polarizations, is attenuated. The attenuator may be tuned by changing the local birefringence of the birefringent fiber.