Showing papers on "Fiber laser published in 1980"
TL;DR: In this paper, the authors reported narrowing and splitting of 7-ps-duration pulses from a mode-locked color-center laser by a 700m-long, singlemode silica-glass fiber, at a wavelength (1.55 \ensuremath{mu}m) of loss and large but negative group-velocity dispersion.
Abstract: This paper reports narrowing and splitting of 7-ps-duration pulses from a mode-locked color-center laser by a 700-m-long, single-mode silica-glass fiber, at a wavelength (1.55 \ensuremath{\mu}m) of loss and large but negative group-velocity dispersion. At certain critical power levels, the observed behavior is characteristic of solitons.
1,844 citations
TL;DR: An efficient coupling from semiconductor lasers in the 1.3-microm range into single-mode fibers with tapered hemispherical ends (TH fiber) is described and it was found that changes in laser characteristics due to reflected light are far less for TH fiber coupling than for flat-end coupling.
Abstract: An efficient coupling from semiconductor lasers in the 1.3-μm range into single-mode fibers with tapered hemispherical ends (TH fiber) is described. Coupling efficiency of more than 35% is attainable with TH fiber coupling. Optimum radius of the end hemisphere is ∼20 μm and is obtained with good reproducibility by drawing the fiber in an arc discharge. It was found that changes in laser characteristics due to reflected light are far less for TH fiber coupling than for flat-end coupling. Stable coupling modules using TH fiber coupling were fabricated for system use.
143 citations
TL;DR: The generation in an optical-fiber waveguide of a spectral continuum spanning 29000 cm−1 from the near infrared to the ultraviolet is reported and an unexpected phenomenon is the generation of sum-frequency light derived from the pump frequency and the characteristic Raman Stokes frequencies of fused silica.
Abstract: The generation in an optical-fiber waveguide of a spectral continuum spanning 29000 cm−1 from the near infrared to the ultraviolet is reported. A Q-switched and mode-locked Nd:YAG laser is used to excite the fiber. An unexpected phenomenon is the generation of sum-frequency light derived from the pump frequency and the characteristic Raman Stokes frequencies of fused silica. This light is observed as visible light in cladding modes of the fiber.
116 citations
TL;DR: In this article, a hemispherical microlens is fabricated on the end of a single-mode fiber by an electric arc discharge technique, which improves coupling efficiency between InGaAsP lasers with buried heterostructure geometry and singlemode fiber.
Abstract: A hemispherical microlens is fabricated on the end of a single-mode fiber by an electric arc discharge technique. It improves coupling efficiency between InGaAsP lasers with buried heterostructure geometry and single-mode fiber. The lowest coupling loss of 2.9 dB is achieved with the optimum lens radius of 8.5 μm. This loss is 4.4 dB lower than that with a butt joint. Experimental results of coupling efficiency and alignment tolerances in coupling with different lens radii in the range of 3.5-17 \mu m are discussed in detail. The results are in good agreement with theoretical values derived by Gaussian beam and paraxial ray approximations.
108 citations
TL;DR: In this article, a design method for a miniature optical lens tipped on a singlemode fiber end to improve power coupling from a semiconductor laser is described, and the optimum coupling conditions and the obtained coupling efficiency are represented in terms of laser beam and fiber parameters.
Abstract: A design method for a miniature optical lens tipped on a single-mode fiber end to improve power coupling from a semiconductor laser is described. The lens shapes studied are hemispherical, hemicylindrical, and hemiellipsoidal. The optimum coupling conditions and the obtained coupling efficiency are represented in terms of laser beam and fiber parameters. Preferable ranges of hemispherical and hemicylindrical lenses are classified according to the laser and fiber mode spot sizes. Fiber axis offset and tilt effects on coupling efficiency are also studied.
90 citations
Patent•
28 Feb 1980TL;DR: A fiber optic device consisting of an optical fiber/interference filter combination finds useful application in optical communication systems for wavelength selection or bandwidth selection from a multiwavelength light source or emitter as discussed by the authors.
Abstract: A fiber optic device basically comprising an optical fiber/interference filter combination finds useful application in optical communication systems for wavelength selection or bandwidth selection from a multiwavelength light source or emitter. If the emitter is a semiconductor laser, the device may be also employed to provide single longitudinal mode control at the selected wavelength or bandpass.
74 citations
TL;DR: In this article, the average connection loss of a C-type, plug-in type, and U-link connector has been found to be 0.4, 0.34, and 0.62 dB, respectively.
Abstract: Various optical fiber connectors using a graded-index fiber have been fabricated and good performances have been obtained during field trial tests. The average connection loss of a C -type, plug-in type, and U -link connector has been found to be 0.4, 0.34, and 0.62 dB, respectively. A new field assembly (FA) type connector using a precision made ceramic capillary has also been developed. This FA type connector is fabricated for use with single-mode fibers, and has a connection loss of 0.56 and 0.52 dB at 0.85 and 1.3 μm, respectively. By using coupling experiments between laser diodes and single-mode fibers, a laser module with a coupling loss of 1.8 dB under optimum alignment conditions has been fabricated.
36 citations
30 citations
TL;DR: In this paper, an optical filter is employed to transport a 15-ns light pulse from a high power ruby laser for precise triggering of a gas filed high voltage spark gap, and the overall throughput efficiency of the optical system was measured as 62 percent.
Abstract: An optical filter is employed to transport a 15-ns light pulse from a high power ruby laser for precise triggering of a gas filed high voltage spark gap. The maximum power density that can be transmitted by the fiber is limited to 6 × 1012 W/m2 above which laser induced damage occurs on the fiber entrance face. The overall throughput efficiency of the optical system was measured as 62 percent. Results are presented for the switching delay time and associated jitter for various mixtures of A and N2 gas, and as a function of the voltage across a pulse-charged Blumlein generator gap. Pulse charging of the Blumlein generator was accomplished by a three-stage Marx generator, resulting in output voltages up to 250 kV. It was conclusively demonstrated that an optical fiber will transport a sufficiently intense laser pulse to evince subnanosecond jitter in the triggering of a pressurized gas switch under the conditions studied.
22 citations
01 Oct 1980
TL;DR: Two types of semiconductor devices are available for use as light sources in fiber transmission systems: light-emitting diode (LED) and semiconductor laser (SRL).
Abstract: Two types of semiconductor devices are available for use as light sources in fiber transmission systems. The simpler device, the light-emitting diode (LED), emits light in many directions and is useful with large core diameter, multimode fibers. The more complicated semiconductor laser emits more collimated light and can couple 10-100 times more power into a multimode fiber and can also be efficiently coupled to small-core single-mode fibers. LED's will be adequate for use in the more numerous data bus and low-to-medium capacity transmission systems, and will be used whenever possible because of their simpler driving circuit requirements, lower temperature sensitivity. and lower cost. Semiconductor laser with their higher power and narrower emission spectrum will be required for high-capacity and long-span transmission systems.
22 citations
TL;DR: To study profile dispersion effects on transmission bandwidth in high-bandwidth graded-index fibers, baseband frequency responses of various graded- index fibers with different profile parameters have been characterized in the 0.78-1.50-microm wavelength range.
Abstract: To study profile dispersion effects on transmission bandwidth in high-bandwidth graded-index fibers, baseband frequency responses of various graded-index fibers with different profile parameters have been characterized in the 078–150-μm wavelength range The test graded-index fibers were made by the MCVD technique Intrinsic intermodal dispersions of these fibers were determined using a combination of a GaAlAs laser and a grating monochromator, a mode-locked Nd:YAG laser, an InGaAsP/InP laser, and stimulated Raman scattering in a single-mode fiber as the light sources Transmission bandwidth functional dependences on wavelength are presented The transmission bandwidth of the individual fibers changed by more than 400% within the experimental spectral range The maximum transmission bandwidth so far observed was 374 GHz·km at 1225-μm wavelength for a fiber with 020 NA Transmission bandwidth spectra were compared with computer calculated results based on Olshansky’s theory
TL;DR: In this paper, the oscillation linewidth of CW fiber Raman laser has been reduced from typical uncontrolled values of 200 GHz to 9 GHz by employing prisms, gratings, and etalons in various resonator configurations.
Abstract: The oscillation linewidth of CW fiber Raman lasers has been reduced from typical uncontrolled values Of 200 GHz (approximately 0.2 nm for 528 nm radiation) to 9 GHz by employing prisms, gratings, and etalons in various resonator configurations. Further reduction is limited by four-wave mixing and stimulated Brillouin scattering. Although four-wave mixing limits bandwidth reduction, the results demonstrate the use of this nonlinear process for intensity stabilization.
TL;DR: In this paper, the average contrast of coherent light from a GaA1As double-hetero-structure laser diode that has been transmitted through a multi-mode optical fiber was analyzed.
TL;DR: A new laser-to-fiber coupling scheme, which eliminates unstable phenomena caused by optical feedback, is proposed and demonstrated experimentally.
Abstract: A new laser-to-fiber coupling scheme, which eliminates unstable phenomena caused by optical feedback, is proposed and demonstrated experimentally. This coupling module contains a packaged diode laser, two lenses, and a beveled-end fiber. Depending on the beveled angle, the reflected light beam from the fiber will be displaced with respect to the emitted light beam at the laser facet, and stabilization of laser output power and spectrum are achieved.
22 Aug 1980
TL;DR: In this article, the authors used short (<2 m) links of polycrystalline KRS-5 (thallium bromoiodide) fiber to relay information to remote photodetectors.
Abstract: Advances in the technology of fabricating IR transmissive fiber waveguides have resulted in the development of fibers that offer unique solutions to near and long-term IR systems problems. Short (<2 m) links of polycrystalline KRS-5 (thallium bromoiodide) fiber have already been successfully used to relay information to remote photodetectors. Future long-distance communications links may take advantage of the extremely low loss potential (~10-3 dB/km) predicted theoretically for a large class of IR fiber materials near 5 µm.© (1980) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
TL;DR: In this paper, a hermetically encapsulated AlGaAs laser diode used as an optical source in a light-wave communication system is described, which includes the mechanical and optical design of the encapsulation, the technique used in assembly, and a review of the environmental tests that were used to establish the design capability of the completed device.
Abstract: A hermetically encapsulated AlGaAs laser diode used as an optical source in a light-wave communication system is described. The laser description includes 1) the mechanical and optical design of the encapsulation; 2) the technique used in assembly of the encapsulation; and 3) a review of the environmental tests that were used to establish the design capability of the completed device.
TL;DR: In this article, the first demonstration of all-optical parallel logic operations such as A/D conversion and OR operations for digital optical computers using the device as an optical switch array was presented.
Abstract: A fiber laser plate exhibits sharp transition and high contrast. We describe the first demonstration of all‐optical parallel logic operations such as A/D conversion and the AND and OR operations important for digital optical computers using the device as an optical switch array.
TL;DR: In this paper, the FIR laser cavity was placed inside the resonator of a pump TE CO2 laser, and the results of FIR laser actions in D2O and CH3OH were observed.
Abstract: A novel compact FIR laser system was constructed. The FIR laser cavity was placed inside the resonator of a pump TE CO2 laser. With this system, FIR laser actions in D2O and CH3OH were observed. Five new lines were found in CH3OH.
TL;DR: The intrinsic diameter of the noncircular cross section of an unclad optical fiber is defined and determines the fiber dimension by studying the forwardscattering pattern from the fiber illuminated by a laser beam perpendicular to its axis.
Abstract: In this paper, the intrinsic diameter of the noncircular cross section of an unclad optical fiber is defined and determines the fiber dimension. Its value can be determined by studying the forwardscattering pattern from the fiber illuminated by a laser beam perpendicular to its axis. A knowledge of the shape of the fiber is not necessary. The suggested method is nondestructive. Moreover, it provides an estimate of the deformation of the fiber cross section.
TL;DR: Duchemin et al. as mentioned in this paper showed that the undoped active layer in the VPE structure Laser Grown by Low-Pressure Metallorganic Chemicalmaterial is n-type (verified by EBIC traces) while Zn diffusion Vapor Deposition is typically p-type.
Abstract: TP-B2 Room-Temperature of a GaInAsPllnP Double-Heterotwo important ways: 1) the undoped active layer in the VPE structure Laser Grown by Low-Pressure Metallorganic Chemicalmaterial is n-type (verified by EBIC traces) while Zn diffusion Vapor Deposition.-J. P. Hirtz and J. P. Duchemin, Thomsonin LPE makes the undoped active typically p-type in that case; CSF, Laboratoire Central de Recherche, Domaine de Corbe2) the upper and lower confining layers are both InP binaries ville, 91401 Orsay, France. in the VPE material, insuring maximum carrier confinement . .