Showing papers on "Saturable absorption published in 1993"
TL;DR: A self-consistent generalization of the Maxwell-Bloch formulation is presented here for a nonlinear system of saturable two-level atoms interacting with the electromagnetic field, under the condition that the atomic density is such that near-dipole-Dipole interactions, which lead to local-field corrections, cannot be neglected.
Abstract: A self-consistent generalization of the Maxwell-Bloch formulation is presented here for a nonlinear system of saturable two-level atoms interacting with the electromagnetic field, under the condition that the atomic density is such that there are, on the average, many atoms within a cubic resonance wavelength such that near--dipole-dipole interactions, which lead to local-field corrections, cannot be neglected.
153 citations
TL;DR: In this paper, a modified equation describing the laser field in a passively mode-locked laser is presented, which includes a fast saturable absorber which is bleached only over a limited intensity-range.
146 citations
TL;DR: Supporting evidence is presented and true self-starting is demonstrated in self-stabilized, passively mode-locked Ti:sapphire and erbium fiber lasers that use fast saturable absorbers.
Abstract: Mode pulling and etalon effects have been claimed to prevent self-starting in passively mode-locked lasers that use fast saturable absorbers. A unidirectional ring geometry significantly reduces backscatter coupling and thus should facilitate self-starting. We present supportive evidence and demonstrate true self-starting in self-stabilized, passively mode-locked Ti:sapphire and erbium fiber lasers.
144 citations
TL;DR: The operation of a diode-pumped monolithic self-Q-switched Cr,Nd:YAG laser in which the codoped ions create saturable absorption for Nd(3+) laser emission at 1064 nm is reported.
Abstract: We report the operation of a diode-pumped monolithic self-Q-switched Cr,Nd:YAG laser in which the codoped ions create saturable absorption for Nd3+ laser emission at 1064 nm. With a 70-μm beam diameter in the gain medium, the Q-switched pulse has a duration of 3.5 ns and a peak power of 2 kW. The output is linearly polarized with an extinction ratio of 600:1. The pulse-to-pulse intensity fluctuation is less than the instrument resolution of 0.25%. A 5-mm-long KTP crystal butted against the monolithic cavity produces 2-ns-long pulses at 532 nm with a peak power-conversion efficiency of 30%.
111 citations
TL;DR: In this paper, the saturation of the optical absorption in V 3+ : YAG crystal is investigated and the absorption cross section of tetrahedral V 3 + at 1.08 μm is estimated to be 8.2±2.5x10 -18 cm 2.
88 citations
TL;DR: Using a polarisation-maintaining erbium-doped fiber near the zero dispersion wavelength and a bulk InGaAsP saturable absorber, the authors in this article passively model a fiber laser to generate nearly transform-limited 320 fs pulses with 40pJ energy.
Abstract: Using a polarisation-maintaining erbium-doped fibre near the zero dispersion wavelength and a bulk InGaAsP saturable absorber, the authors passively modelock a fibre laser to generate nearly transform-limited 320 fs pulses with 40pJ energy. The laser produces a stable state of linear polarisation and the semiconductor, which acts both as a slow and fast saturable absorber, self-starts the laser.
76 citations
TL;DR: In this paper, the reverse saturable absorption properties of these doped xerogels have been compared to those of reference solutions of Aluminophthalocyanine (APC) and fullerene carbon 60 (C60).
Abstract: Aluminophthalocyanine (APC) and fullerene carbon 60 (C60) have been studied encaged in different silica matrices. The reverse saturable absorption properties of these doped xerogels have been compared to those of reference solutions of APC and C60. We show that reverse saturable absorber molecules retain their properties even when they are enclosed in the pores of a solid xerogel matrix.
74 citations
TL;DR: Self-Q-switching operation of a miniature diode-end-pumped Cr,Nd:YAG laser in which the chromium ions act as a saturable absorber for the Nd3+ laser emission at 1064 nm is reported.
Abstract: We report self-Q-switching operation of a miniature diode-end-pumped Cr,Nd:YAG laser in which the chromium ions act as a saturable absorber for the Nd3+ laser emission at 1064 nm. The laser output is highly polarized, with an extinction ratio of 600:1. The use of laser host crystal doped with saturable absorber can lead to the development of monolithic Q-switched solid-state lasers.
70 citations
TL;DR: A new mode-locking mechanism is proposed, which is referred to as Kerr-shift mode locking, in which the wavelength-dependent intracavity aperture and self-phase modulation in Nd:glass combine to produce a self-wavelength shift that reduces intracvity losses for femtosecond pulses.
Abstract: We produced transform-limited pulses as short as 130 fs with 160-mW average output power from a passively mode-locked Nd:glass laser. This is to our knowledge the first demonstration of an intracavity semiconductor antiresonant Fabry–Perot saturable absorber continuously starting a Kerr-induced passively mode-locked laser. The antiresonant Fabry–Perot saturable absorber, even with dispersion compensation, produced only picosecond pulses, and femtosecond performance was observed only with the addition of an intracavity long-pass wavelength filter. We propose a new mode-locking mechanism, which we refer to as Kerr-shift mode locking, in which the wavelength-dependent intracavity aperture and self-phase modulation in Nd:glass combine to produce a self-wavelength shift that reduces intracavity losses for femtosecond pulses.
68 citations
TL;DR: In this paper, a numerical study of a three-level laser model with a saturable absorber is presented, and the question of stability is explored by examining small perturbations of the steady-state solutions of the rate equations.
Abstract: A numerical study of a three-level laser model that includes a saturable absorber is presented. The theory models the laser as a lumped element. This assumption is valid as long as the laser pulses are much longer than the cavity. The model is intended to be somewhat representative of an erbium-doped fiber laser without trying to mimic the operating parameters of such a laser too closely. As expected, the presence of the saturable absorber causes the laser to be unstable under certain operating conditions. The question of stability is explored by examining small perturbations of the steady-state solutions of the rate equations. It is found that the predictions of this stability analysis are in excellent agreement with the behavior of the solutions of the full time-dependent rate equations. It is also found that under certain conditions the laser may pass from pulsed to stable operation simply by raising the pump power. >
68 citations
TL;DR: A self-starting passively mode-locked diode-pumped neodymium fiber laser with a semiconductor antiresonant Fabry-Perot saturable absorber (A-FPSA) is demonstrated for the first time to the authors' knowledge.
Abstract: A self-starting passively mode-locked diode-pumped neodymium fiber laser with a semiconductor antiresonant Fabry-Perot saturable absorber (A-FPSA) is demonstrated for the first time to our knowledge. Mode locking can be initiated and maintained by the semiconductor absorber, and pulse durations down to 260 fs are routinely obtained. Alternatively, shorter pulses (60 fs) were generated by exploition of nonlinear polarization evolution in the fiber (in combination with a stronger pump source) where the A-FPSA simply initiates the pulse-forming process.
TL;DR: In this article, the authors investigate a tandem geometry with two passive nonlinear elements, one placed in the focal plane of a lens and the second placed upstream of the focal position to protect the material at focus from damage.
Abstract: We present results of optical limiting experiments designed to study optical geometries for increasing the dynamic range over which limiters function without incurring optical damage. Specifically, we investigate a tandem geometry with two passive nonlinear elements, one placed in the focal plane of a lens and the second placed “upstream” of the focal position to protect the material at focus from damage. To provide a proof-of-principle demonstration of this geometry, simple limiters consisting of combinations of reverse saturable absorber dyes and a carbon black suspension in thin cells were tested. Our results show that a substantial increase in device performance can be achieved by use of a tandem limiter geometry. Simple modelling predicts that the dynamic range of a separate-element tandem limiter is given by the product of the dynamic ranges of the individual component limiting elements, in agreement with our experimental results.
TL;DR: Passive Q switching of an Er:phosphate glass laser using Er:Ca5(PO4)3F (Er:FAP) as a saturable absorber intracavity (IC) load is described in this article.
Abstract: Passive Q switching of an Er:phosphate glass laser using Er:Ca5(PO4)3F (Er:FAP) as a saturable absorber intracavity (IC) load is described for the first time. Q‐switched output was obtained consisting of a 6‐mJ single pulse of 83 ns full width at half maximum, with a 20% efficiency relative to the corresponding free‐running output in the absence of the IC Er:FAP load.
TL;DR: In this paper, an increase in transmission coefficient at high fluences, following low-fluence reverse saturable absorption (induced absorption), is demonstrated for the tricarbocyanine dye, HITCI.
TL;DR: In this article, the authors reported direct observations of all-optical mirrorless bistability associated with saturable absorption in three kinds of bacteriorhodopsin (BR) samples: wild type BR in water solution and dispersed in thin films of a polymer matrix as well as water solution of the genetically engineered mutant BRD96N.
Abstract: We report direct observations of all‐optical mirrorless bistability associated with saturable absorption in three kinds of bacteriorhodopsin (BR) samples: wild‐type BR in water solution and dispersed in thin films of a polymer matrix as well as water solution of the genetically engineered mutant BRD96N. The experiments are carried out with picosecond pulses at 532 nm. The values measured for the saturation intensity are explained in terms of the relaxation of the excited M state population to the B state of the BR photocycle for the three kinds of samples studied.
TL;DR: It is shown, both theoretically and experimentally, that stable single-longitudinal-mode operation, with transform-limited spectral linewidth and without pulse-to-pulse mode competition, can be obtained in a monolithic self-Q-switched Cr,Nd:YAG solid-state laser with a distributed saturable absorber.
Abstract: It is shown, both theoretically and experimentally, that stable single-longitudinal-mode operation, with transform-limited spectral linewidth and without pulse-to-pulse mode competition, can be obtained in a monolithic self-Q-switched Cr,Nd:YAG solid-state laser with a distributed saturable absorber. In this system, the lasing mode establishes a loss grating and thereby stabilizes itself.
TL;DR: It is demonstrated that the slow component provides the self-starting mechanism and without significant Kerr lens contribution the fast component is necessary for steady-state pulse formation in passively cw mode-locked solid-state lasers.
Abstract: The semiconductor antiresonant Fabry–Perot saturable absorber (A-FPSA) has a bitemporal absorption response with a slow time component that is due to carrier recombination and a fast time component that is due to intraband thermalization. We demonstrate that the slow component provides the self-starting mechanism and without significant Kerr lens contribution the fast component is necessary for steady-state pulse formation in passively cw mode-locked solid-state lasers. The carrier lifetime of the bitemporal A-FPSA was varied by the molecular-beam-epitaxy growth temperature to characterize its influence on the self-starting and self-Q-switching dynamics of cw mode-locked Nd:YLF and Nd:YAG lasers. The A-FPSA carrier lifetime and the top reflector of the A-FPSA can be adjusted to optimize the self-starting performance and to prevent self-Q-switching of cw mode-locked solid-state lasers.
TL;DR: Using a semiconductor saturable absorber, an erbium-doped fiber laser has been passively mode locked to yield pulses of 840 fs with pulse energies of 0.85 nJ.
Abstract: Using a semiconductor saturable absorber, an erbium‐doped fiber laser has been passively mode locked to yield pulses of 840 fs with pulse energies of 0.85 nJ. Stable mode locking at the fundamental roundtrip frequency and also at the second and third harmonic has been achieved.
TL;DR: In this paper, GSGG has been utilized for the first time to provide a saturable absorber Q -switch for the ruby laser. Butts et al. used GSGG to provide the switch for single output pulse operation (100 mJ and 27 ns duration) with efficiencies relative to the free-running ruby laser operation of 25-30% was obtained.
TL;DR: In this paper, passive Q switching of Nd:YAG lasers with the use of a bulk InGaAsP film, grown on an InP substrate by liquid-phase epitaxy, as an intracavity saturable absorber was reported.
Abstract: We report passive Q switching of Nd:YAG lasers with the use of a bulk InGaAsP film, grown on an InP substrate by liquid-phase epitaxy, as an intracavity saturable absorber. The single Q-switched pulse had a maximum energy of 1.65 mJ with a 20-ns duration. The simple technology is easily extendible to any infrared solid-state laser.
TL;DR: In this article, the starting dynamic of mode-locked solid-state lasers is analyzed taking into account the gain reduction by the total random radiation, and a simple self-starting condition is derived, depending on the pump-rate, the gain cross section, the nonlinear coefficient, gain bandwidth and the resonator length.
TL;DR: The frequency stability of the free-running lasers was sufficient to allow locking of the laser repetition rate to a synthesizer by using a phase-lock-loop feedback system.
Abstract: We report passively mode-locked diode-pumped Nd:YAG and Nd:YLF lasers that use an antiresonant Fabry–Perot saturable absorber. For Nd:YLF at 1047 nm, we achieved pulses of 5.1 ps FWHM with 225 mW of average power. For Nd:YAG at 1064 nm, we achieved pulse widths of 8.7 ps with 100 mW of average power. Both lasers ran at a repetition rate of 100 MHz. The frequency stability of the free-running lasers was sufficient to allow locking of the laser repetition rate to a synthesizer by using a phase-lock-loop feedback system.
Proceedings Article•
02 May 1993
TL;DR: In this article, the authors reported the operation of a diode-pumped monolithic self-Q-switched CR,Nd:YAG laser in which the codoped ions create saturable absorption for Nd" laser emission at 1064 nm.
Abstract: We report the operation of a diode-pumped monolithic self-Q-switched Cr,Nd:YAG laser in which the codoped ions create saturable absorption for Nd" laser emission at 1064 nm. With a 70-/um beam diameter in the gain medium, the Q-switched pulse has a duration of 3.5 ns and a peak power of 2 kW. The output is linearly polarized with an extinction ratio of 600:1. The pulse-to-pulse intensity fluctuation is less than the instrument resolution of 0.25%. A 5-mm-long KTP crystal butted against the with a peak power-conversion efficiency of 30%.
TL;DR: Numerically the validity of using nonlinear gain to stabilize soliton transmissions where the filters are incorporated to reduce the Gordon–Haus frequency shift is demonstrated.
Abstract: In soliton transmission systems with bandwidth-limited amplifications, solitons tend to be destroyed during long-distance propagation owing to the interaction with linear dispersive waves, which are generated from solitons by the filtering and amplified by the excess gain around the filter center frequency. Recently Kodama et al. [Electron. Lett. 28, 1981 (1992)] suggested that the instability may be suppressed by introducing amplifiers with nonlinear gain, or gain and saturable absorption in combination. We demonstrate numerically the validity of using nonlinear gain to stabilize soliton transmissions where the filters are incorporated to reduce the Gordon–Haus frequency shift.
TL;DR: A nonlinear mirror consisting of an InGaAs/InP multiple-quantum-well saturable absorber integrated with a Bragg reflector stack has been used to passively mode-lock a fiber laser in an extremely simple and advantageous linear-cavity configuration as mentioned in this paper.
Abstract: A nonlinear mirror consisting of an InGaAs/InP multiple-quantum-well saturable absorber integrated with a Bragg reflector stack has been used to passively mode-lock a fiber laser in an extremely simple and advantageous linear-cavity configuration. To date, pulses as short as 7.6 ps have been observed. >
TL;DR: In this article, a laser with an intracavity saturable absorber showing optical bistability is investigated through the simultaneous injection of modulation and noise on the pumping parameter; stochastic resonance is exhibited in the measured signal-to-noise ratio of the laser intensity.
Abstract: A laser with intracavity saturable absorber showing optical bistability is investigated through the simultaneous injection of modulation and noise on the pumping parameter; stochastic resonance is exhibited in the measured signal-to-noise ratio of the laser intensity.
TL;DR: In this paper, active, passive, and hybrid mode locking of a monolithic extended-cavity semiconductor laser with an integrated saturable absorber have been demonstrated, achieving a repetition rate of 8.6 GHz, 6.2 ps, and 4.4 ps, respectively.
Abstract: Active, passive, and hybrid mode locking of a monolithic extended‐cavity semiconductor laser with an integrated saturable absorber have been demonstrated. Actively mode locked at a repetition rate of 8.6 GHz, 6.2 ps pulses were measured. Hybrid mode locking resulted in 4.4 ps pulses. The extended‐cavity laser also exhibits self‐starting passive mode locking at a repetition rate of 8.57 GHz with 5.5 ps pulses. A broad spectrum allows wavelength selectivity over a range of 15 nm with little change in the pulse width.
TL;DR: In this article, the authors obtained 230 fs, 25 W pulses from conventional mode-locked AlGaAs laser diodes with highly-reflecting external cavities, which were used with a region of saturable absorption created by ion implantation.
Abstract: 230 fs, 25 W pulses are obtained from conventional mode-locked AlGaAs laser diodes with highly-reflecting external cavities. Uncoated commercial diodes are used with a region of saturable absorption created by ion implantation. The overall pulse performances are believed to be among the best reported from simple electrically-pumped laser diodes without using additional amplifier sections.
TL;DR: Pulses as short as 2.3 ps have been generated by passive mode locking of a lamp-pumped Nd:YLF laser with a microdot mirror mode locker for Kerr-lens mode-locking (KLM) saturable absorber action and a compact Gires-Tournois interferometer for dispersion compensation.
Abstract: Pulses as short as 2.3 ps have been generated by passive mode locking of a lamp-pumped Nd:YLF laser with a microdot mirror mode locker for Kerr-lens mode-locking (KLM) saturable absorber action and a compact Gires–Tournois interferometer for dispersion compensation. KLM was initiated with an acousto-optic modulator. Average output powers of 800 mW have been achieved. This result demonstrates the potential use of KLM for generating near-bandwidth-limited pulses from high-power lamp-pumped sources.
TL;DR: Pulse generation in a two-photon laser is investigated theoretically and a simple model including dispersion, linear absorption, and two- photon saturable gain yields stable mode-locked pulses with a sech2 intensity profile.
Abstract: Pulse generation in a two-photon laser is investigated theoretically. A simple model including dispersion, linear absorption, and two-photon saturable gain yields stable mode-locked pulses with a sech2 intensity profile. Unlike as with self-phase-modulation methods, the pulse width is independent of the nonlinear parameters.