Showing papers on "Tunable laser published in 1986"
Book•
01 Jan 1986TL;DR: In this paper, the current status and future applications of lightwave transmission of longwavelength semiconductor lasers emitting near 1.3 and 1.55-mu m are described, and bit-error-rate curves for a transmission experiment at 8 Gb/s over 76 km of fiber are shown.
Abstract: The current status and future applications to lightwave transmission of long-wavelength semiconductor lasers emitting near 1.3 and 1.55- mu m are described. Bit-error-rate curves for a transmission experiment at 8 Gb/s over 76 km of fiber are shown, and schematics of a high-speed distributed feedback laser and a multielectrode distributed Bragg reflector laser are presented. >
1,119 citations
TL;DR: In this article, the effects of feedback on the spectra of 1.5-μm DFB lasers from feedback power ratios as low as -80 dB up to -8 dB were measured.
Abstract: We have measured the effects of feedback on the spectra of 1.5-μm DFB lasers from feedback power ratios as low as -80 dB up to -8 dB. Five distinct regimes of effects are observed with well defined transitions between them. The dependence of these effects on the distance to the reflection is also investigated.
729 citations
TL;DR: In this article, a single-mode Q-switched Q-mode fiber laser source is described, which is tunable over 25 nm in the wavelength region of 1.55 μm and produces in excess of 2 W peak power in a Qswitched mode.
Abstract: A new single-mode fibre laser source is described. The laser is tunable over 25 nm in the wavelength region of 1.55 μm and produces in excess of 2 W peak power in a Q-switched mode.
214 citations
TL;DR: In this article, the authors analyzed the noise of injection-locked semiconductor lasers by rate equations including the spontaneous emission noise, and the side mode suppression and the relative intensity noise of the locked laser (slave laser) were given for different wavelengths detuning between the master and slave laser and for different linewidth enhancement factors α.
Abstract: The noise of injection-locked semiconductor lasers is analyzed by rate equations including the spontaneous emission noise. The side mode suppression and the relative intensity noise (RIN) of the locked laser (slave laser) are given for different wavelengths detuning between the master and slave laser and for different linewidth enhancement factors α. For large α, locking is difficult to achieve, whereas extremely low noise may be obtained for injection-locked lasers with a low linewidth enhancement factor.
185 citations
TL;DR: Tunable CW lasing was achieved for the first time in an Er3+-doped fiber laser, which has an overall tuning range of 25 nm in the region of \lambda = 1.54 /mu m as mentioned in this paper.
Abstract: Tunable laser action has been obtained in Nd3+- and Er3+-doped single-mode fiber lasers. In the case of the Nd3+-doped fiber, an extensive tuning range of 80 nm has been achieved. Tunable CW lasing also has been observed for the first time in an Er3+-doped fiber laser, which has an overall tuning range of 25 nm in the region of \lambda = 1.54 /mu m.
139 citations
TL;DR: The use of photorefractive four-wave mixing for coupling and locking of lasers is discussed and a demonstration of the double phase-conjugate mirror and the semilinear passive phase- Conjugate Mirror, pumped simultaneously by different lasers, is described.
Abstract: We discuss the use of photorefractive four-wave mixing for coupling and locking of lasers. A demonstration of the double phase-conjugate mirror and the semilinear passive phase-conjugate mirror, pumped simultaneously by different lasers, is described. Cleanup of a distorted laser beam using another local laser and configurations for the phase locking of lasers are discussed.
114 citations
TL;DR: In this paper, photoinduced intramolecular proton transfer was used to generate stimulated radiation with a 10% efficiency using sodium salicylate or 2-( o -hydroxyphenyl)benzimidazole as the active medium.
111 citations
TL;DR: In this article, the temporal response of the third-order nonlinear optical susceptibility in poly bis(toluene sulfonate) of 2,4•hexadiyne•1,6 diol was determined by time-resolved degenerate four-wave mixing using tunable dye laser pulses with 300 fs duration.
Abstract: The temporal response of the third‐order nonlinear optical susceptibility in poly bis( p‐toluene sulfonate) of 2,4‐hexadiyne‐1,6 diol was determined by time‐resolved degenerate four‐wave mixing using tunable dye laser pulses with 300 fs duration. In the material’s absorption region these experiments were combined with saturated absorption techniques yielding a measurement for the excited state lifetime of 1.8 ps. Off resonance the nonlinear response was determined to be optical pulse width limited.
107 citations
CNET1
TL;DR: In this paper, a 1.26 μm optical amplifier with a facet modal reflectivity below 0.0001 has been used in a 58 mm-long grating external cavity.
Abstract: A 1.26 μm optical amplifier with a facet modal reflectivity below 0.0001 has been used in a 58 mm-long grating external cavity. The lasing wavelength has been continuously tuned without mode hopping over a range of 15 nm by combined translation-rotation of the diffraction grating. A linewidth of 20 kHz has been derived from heterodyne beat frequency measurements between two tunable external-cavity lasers.
103 citations
01 Oct 1986
TL;DR: Time-structure and frequency-spectrum measurements of the UC Santa Barbara free-electron-laser oscillator show that for periods shorter than 5 microsec, the laser-frequency changes in unexpected quantized steps, which may be explained in terms of a homogeneously broadened gain profile coupled to a small monotonic drift in electron-beam energy.
Abstract: Time-structure and frequency-spectrum measurements of the UC Santa Barbara free-electron-laser oscillator show that for periods shorter than 5 microsec. The laser operates in a stable single-cavity mode having a strikingly small fractional frequency bandwidth of 10/sup 8/. This constitutes the first demonstration of high-temporal-coherence operation of a free-electron laser. For periods longer than 5 microsec, the laser-frequency changes in unexpected quantized steps, which may be explained in terms of a homogeneously broadened gain profile coupled to a small monotonic drift in electron-beam energy.
100 citations
TL;DR: In this paper, the authors investigated the CW laser properties of the lanthamide hexa-aluminate La 0.9 Nd 0.1 MgAl 11 O 19 at room temperature.
Abstract: We have investigated the CW laser properties of the lanthamide hexa-aluminate La 0.9 Nd 0.1 MgAl 11 O 19 at room temperature. When a 1 cm long crystal is pumped by an Ar+ laser (514 nm) or a Kr+ laser (752 nm), CW emission is obtained with slope efficiencies of 10 and 26 percent, respectively. A four-plate Lyot filter in the cavity forces the LNA crystal to oscillate in either of the two major bands centered al 10 820 A (tuning range 80 A) and 10 545 A (tuning range 35 A).
Patent•
16 Dec 1986TL;DR: In this paper, a coherent optical output light is obtained by using a wavelength stabilized laser and an optical phase locked loop wherein the frequency of the output has the characteristics of high accuracy, high stability and narrow spectral line width.
Abstract: An optical frequency synthesizer and/or sweeper, whereby a coherent optical output light is obtained by using a wavelength stabilized laser and an optical phase locked loop wherein the frequency of the output has the characteristics of high accuracy, high stability and narrow spectral line width The optical phase locked loop comprises a tunable laser, an optical frequency multiplier, an optical frequency shifter and an optical heterodyne detector, wherein the optical phase locked loop is capable of precisely outputting an arbitrary wavelength by feeding back an output optical frequency
TL;DR: In this article, a color center associated with Pb 2+ as impurity in the cubic perovskite KMgF 3 was found to be tunable from 855 to 965 nm.
TL;DR: In this article, a tunable diode laser has been used to observe rotational collisional narrowing or line mixing in the IR absorption spectrum of the Q branch of the sub II - 0 0 exp-0 0 band of CO2 at 1932.
Abstract: A tunable diode laser has been used to observe rotational collisional narrowing or line mixing in the IR absorption spectrum of the Q branch of the (1 1 exp-1 0,0 3 exp-1 0) sub II - 0 0 exp-0 0 band of CO2 at 1932.47/cm over the 100-745 Torr pressure range. The observed absorption coefficients below the band origin are up to 80 percent lower than those calculated on the basis of an isolated Lorentz line approxmation. A simple fitting law is derived for the state-to-state, rotationally inelastic rate constants, on the basis of the known line broadening coefficients; a calculation of the mixing using these rates agrees with observed absorption coefficients to within several percent.
TL;DR: In this article, the ν2 fundamental band of CH2 in its X 3B1 ground electronic state has been studied using tunable diode laser spectroscopy and also the LMR (laser magnetic resonance) technique in the 800 −911 cm−1 and 1030 −1173 cm− 1 regions.
Abstract: The ν2 (bending) fundamental band of CH2 in its X 3B1 ground electronic state has been studied using tunable diode laser spectroscopy and also the LMR (laser magnetic resonance) technique in the 800–911 cm−1 and 1030–1173 cm−1 regions. For the diode laser study, a multiple‐traversal absorption cell was used with Zeeman modulation, and the CH2 radicals were produced by a mild discharge in a flowing mixture of ketene (∼0.3 Torr) and helium (∼2 Torr). Under these conditions, the apparent lifetime of CH2 following cutoff of the discharge was about 1 ms. A total of 53 new transitions with rotational quantum numbers up to N=10, K‘a =3, and Ka =2 were observed to add to the 11 transitions previously measured in this band. A combined analysis of the present data and all the previous pure rotational and ν2 band results on CH2 has yielded an improved set of molecular parameters, including the first determination of centrifugal distortion effects for the dominant spin–spin interaction parameter, D. The present data...
TL;DR: An internally coupled confocal Fabry-Perot interferometer has been developed for both high precision wavelength calibration and stabilization of tunable diode lasers and will facilitate the use of TDLs in sub-Doppler spectroscopy and as local oscillators in heterodyne radiometers.
Abstract: An internally coupled confocal Fabry-Perot interferometer (FPI) has been developed for both high precision wavelength calibration and stabilization of tunable diode lasers (TDL). Our FPI is tunable and thermally stable and works over a large wavelength range (0.6–30 μm)—characteristics that cannot be simultaneously realized with conventional etalons. As part of a versatile wavelength control system the instrument has already considerably improved the quality of our diode laser spectra and will facilitate the use of TDLs in sub-Doppler spectroscopy and as local oscillators in heterodyne radiometers.
TL;DR: A tunable Nd(3+)-doped monomode-fiber laser has been constructed that operates continuously at room temperature and output powers were achieved for the two ranges from pumping by a dye laser operating at 590 nm.
Abstract: A tunable Nd(3+)-doped monomode-fiber laser has been constructed that operates continuously at room temperature. The tuning range covered is 0.900-0.945 and 1.070-1.135 microm. Output powers of 3 mW for 53 mW of absorbed pump and 2 mW for 35 mW of absorbed pump, respectively, were achieved for the two ranges from pumping by a dye laser operating at 590 nm.
TL;DR: In this paper, a general technique for combining laser beams coherently using binary gratings has been developed and experiments were performed with laser beams from a monolithic linear GaAlAs array.
Abstract: A general technique for combining laser beams coherently using binary gratings has been developed. Experiments were performed with lasers from a monolithic linear GaAlAs array. The grating transmittance profile was designed to convert the light beams from the array into a single beam with high efficiency. Optical feedback through the grating locked the lasers together in proper relative phase. The far‐field diffraction pattern of the sum was practically identical in shape to that of a single laser. Coupling efficiencies greater than 80% appear to be feasible with this technique. The method is applicable to a variety of laser systems (gas, solid state, etc.) and is readily extendable to a two‐dimensional array of lasers.
TL;DR: A surface-relief grating on a side-polished single-mode fiber acts as an external Bragg reflector for standard, multilongitudinal-mode 1.3 μm injection lasers as discussed by the authors.
Abstract: A surface-relief grating on a side-polished single-mode fibre acts as an external Bragg reflector for standard, multilongitudinal-mode 1.3 μm injection lasers. With 2 m fibre length, single-mode, 60 kHz linewidth operation at 1 mW is obtained.
TL;DR: In this article, the authors review the current state of phase-locked array design with emphasis on the means for achieving fundamental mode operation, and the potential of various array structures to operate in a single, diffraction limited output beam is evaluated.
Abstract: Semiconductor diode lasers can be combined into monolithic phase-locked arrays that operate to continuous-wave (CW) powers in excess of 1 W and exhibit well-defined output beams to hundreds of mW. Applications of arrays include high-speed optical recording, high-speed printing, free-space communications, and efficient pumping of solid-state lasers. The authors review the current state of phase-locked array design with emphasis on the means for achieving fundamental mode operation. Models for understanding and predicting the behavior of phase-locked arrays are discussed, and the potential of various array structures to operate in a single, diffraction-limited output beam is evaluated.
TL;DR: In this article, a multiple-pass cell was used to enhance the Raman gain and produce an overall quantum conversion efficiency of at least 45 percent in the wavelength range from 0.9 to 5μm.
Abstract: We have obtained continuously tunable coherent radiation in the 1-12 \mu m region via sequential Raman scattering of pulsed-dye-laser radiation in hydrogen. A multiple-pass-cell was used to enhance the Raman gain and produce an overall quantum conversion efficiency of at least 45 percent in the wavelength range from 0.9 to 5μm. At 5 μm, an energy output of 1 mj in a 7 ns pulse at a 10 Hz repetition rate has been obtained. Inherent four-wave mixing initiates the sequential Stokes conversion to the infrared and produces single transverse mode (TEM 00 ) radiation in a 0.2 cm-1bandwidth. We have developed a nonlinear model of the process that includes the effects of diffraction, four-wave mixing, and temporal pulse shape and gives numerical outputs in agreement with experiment.
TL;DR: A detection-sensitivity limit of 1 x 10(-5) to differential absorption from Doppler-broadened NH(3) lines in the 930-cm(-1) region is demonstrated, set by preamplifier noise and the low quantum efficiency of the photodetector.
Abstract: We report the demonstration of two-tone optical heterodyne spectroscopy with a tunable lead-salt diode laser. Using high-frequency modulation of the diode-laser injection current, we demonstrated a detection-sensitivity limit of 1 × 10−5 to differential absorption from Doppler-broadened NH3 lines in the 930-cm−1 region. In our experiment, this limit was set by preamplifier noise and the low quantum efficiency of the photodetector. A substantial increase in sensitivity should be possible by using an improved detector, an improved preamplifier, and higher optical power.
Patent•
08 Dec 1986TL;DR: In this paper, a tunable dye laser has been found particularly suited to selective photothermolysis and a longer pulse duration was obtained by modifying the laser to generate a spatially non-coherent beam.
Abstract: A tunable dye laser has been found particularly suited to selective photothermolysis. A longer pulse duration which makes the system suitable for a wider range of applications is obtained by modifying the laser to generate a spatially noncoherent beam. The optical system at each end of the laser cell, which may include a lens or spherical mirror, refocuses the aperture of the dye cell near to itself so that substantially all light emanating from the dye cell is returned to the dye cell until the light passes through one of the optic systems as a noncoherent laser beam. A tunable intracavity element tunes the laser across the gain curve of the dye solution. The pulse duration of the laser beam can be selected from a range of durations up to about one millisecond.
TL;DR: In this paper, a coupled-rate-equation model of a semiconductor laser incorporating bimolecular recombination and realistic injection current pulse shapes is presented, and theoretical predictions are found to be in excellent agreement with the experimental results.
Abstract: Stable production of 15ps pulses having a peak power of 200 mW from fully gain-modulated, unbiased GaAs double-heterostructure and multiple-quantum-well lasers emitting in the 08 μm-09 μm wavelength range and from InGaAsP double heterostructure lasers emitting in the 12 μm-13 μm range is reported The shortest pulses obtained from GaAs DH lasers show a width as small as 2ps The optical pulses represent the first relaxation oscillation of the laser Special double avalanche generators are developed to produce large injection-current pulses with widths down to 12Sps at repetition rates up to 10 MHz Numerical and approximate analytical solutions of a coupled-rate-equation model of a semiconductor laser incorporating bimolecular recombination and realistic injection current pulse shapes are presented The theoretical predictions are found to be in excellent agreement with the experimental results
TL;DR: The distributed feedback dye laser (DRL) as discussed by the authors is a source of single picosecond pulses tunable in a very wide wavelength range, which can be used for a wide range of applications.
Abstract: The distributed feedback dye laser is a source of single picosecond pulses tunable in a very wide wavelength range Operational principles, experimental arrangements, and recent applications are reviewed in this paper
TL;DR: In this paper, three-dimensional features have been milled into optical materials by scanning a submicron focused gallium ion beam and different shapes are obtained using computer controlled beam placement and dwell time during sputtering.
Abstract: Three‐dimensional features have been milled into optical materials by scanning a submicron focused gallium ion beam. Different shapes are obtained using computer controlled beam placement and dwell time during sputtering. We have used this technique to create micron‐sized facets and reflectors in the active areas of semiconductor lasers. Light output and quantum efficiency measurements indicate that these features are of sufficient quality to fabricate monolithic integrated optical devices. Some of the applications currently being investigated are laser‐detector pairs, coupled cavity lasers, lasers with integral lenses, distributed feedback lasers, confocal cavities, and laser cavity length tuning.
TL;DR: Injection control of a tunable Ti:sapphire laser using a narrow-bandwidth pulsed dye laser operating at a wavelength removed from the peak of the Ti:Sapphire-laser gain curve is reported.
Abstract: Injection control of a tunable Ti:sapphire laser using a narrow-bandwidth pulsed dye laser operating at a wavelength removed from the peak of the Ti:sapphire-laser gain curve is reported. The free-running Ti:sapphire laser had broadband laser emission from 750 to 790 nm. Injection at 727 nm resulted in essentially complete energy extraction at that wavelength in a 2.5-pm bandwidth matching the injection source.
TL;DR: In this paper, the effect of nonequivalent Cr sites on room temperature tunable-laser action has been investigated from the absorption and the excitation spectra, and a broad absorption band peaked near 750 nm does not contribute to the Cr emission.
Abstract: Room-temperature tunable-laser action has been observed in Cr-doped SrAlF5. The measured tuning range is 852–947 nm in a quasi-cw laser mode. The effect of nonequivalent Cr sites in SrAlF5 is studied from the absorption and the excitation spectra. A broad absorption band peaked near 750 nm does not contribute to the Cr emission and appears to be associated with a nonradiative site.
TL;DR: In this paper, the infrared spectrum of the ν6 asymmetric deformation band of hydrogen peroxide (H2O2) was studied in the region 1100-1350 cm−1 using the two techniques of Fourier transform spectroscopy at 0.02cm−1 resolution and tunable diode laser spectroscopic at Doppler-limited resolution.
TL;DR: In this article, the first observation of strong magnetic field tuning of laser emission from Cd1−xMnxTe/Cd 1−yMnyTe multiple quantum well structures was reported.
Abstract: We report the first observation of strong magnetic field tuning of laser emission from Cd1−xMnxTe/Cd1−yMnyTe multiple quantum well structures. The spectral peak of the stimulated emission shifts to lower energy with increasing field at a rate of 3.4 meV/T to a maximum shift of 34 meV at 10 T. This is about five times slower than in bulk Cd1−xMnxTe with a comparable x value. Stimulated emission was observed for samples cooled to 1.9 K when optically pumped with a Nd:YAG laser.