Dye Laser Oscillator Research Articles

Fluctuations in the phase-conjugate signal generated via degenerate four-wave mixing

The excess fluctuations of the phase-conjugate (PC) signal generated via pulsed degenerate four-wave mixing (DFWM) in sodium vapor are investigated. Various dye-laser oscillator and amplifier combinations are employed to trace the sources of these fluctuations. For DFWM driven by an externally-stabilized cw dye-laser oscillator amplified with a dye system pumped by the smoothed pulses of a Nd:YAG laser, the PC excess fluctuations are very highly correlated with the energy fluctuations of the input amplified dye-laser pulses. Thus, input-pulse selection on the basis of energy alone permits observation of the quantum-mechanical fluctuations of the PC signal.

A cascade pumped picosecond dye laser system

A picosecond dye laser system producing 4 μJ in a 10 ps pulse is described. This highly stable compact system consists of a nitrogen laser and two cascade pumped dye laser oscillators followed by one amplifier. The Roess-Lin cavity transient technique was applied to compress the input 60 μJ 300 ps N <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> pulse twice to produce a final output duration of 10 ps. Discrete output wavelengths can be varied by changing the dye laser solution. Spectral and temporal measurements were performed to characterize this laser. A broad spectral emission of ∼ 160 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> was observed, consistent with the observed fine temporal structures of 0.09 ps. A model rate equations calculation was also performed with parameters pertinent to the present laser system. This picosecond laser system should find applications in testing and calibration in the picosecond timescale.

Narrow linewidth, high prf copper laser-pumped dye-laser oscillators

Design and operating characteristics are reported for high prf copper laser-pumped rhodamine 590 dye-laser oscillators using simple Littrow-mounted or grazing-incidence grating cavities incorporating double-prism beam expanders. Conversion efficiencies from the 2-W, λ510.6-nm pump beam at the λ575-nm peak of the dye tuning band are 4–5% for linewidths in the subgigahertz range down to 650 MHz at a pulse repetition frequency of 8 kHz. Background amplified spontaneous emission intensity is low, typically 1% of tunable laser intensity for the Littrow-grating cavity and only 0.1% for the grazing-incidence grating cavity.

Thermal effects in double prism dye laser cavities

Output power, beam divergence, and frequency stability in a double-prism dye laser cavity have been investigated as a function of temperature. For rhodamine 6G dye, it has been found that output power decreases by nearly 34 percent, beam divergence increases from 4.5 to 6.5 mrads, and the laser frequency is shifted by as much as 2 cm-1, for an increase of 10°C above room temperature. The efficiency of the double-prism dye laser oscillator employed here was 18 percent (for N 2 laser pump) at a linewidth of 0.07 cm-1(FWHM). Laser linewidth did not vary in the temperature range investigated here.

Amplified spontaneous emission (ASE) in laser oscillators and amplifiers

Dye-laser oscillators and amplifiers are studied theoretically with inclusion of amplified spontaneous emission (ASE). Assuming pencil-like geometry in both cases, laser signal intensity and ASE intensity are described with appropriate photon-transport equations. In particular, there exist different boundary conditions fox both fluxes in the laser cavity case due to the different feedback behavior of an optical resonator for laser modes and ASE modes. The interaction of laser output and ASE intensity is discussed in detail, including laser output optimization without and with ASE effects. For single- and double-pass amplifiers closed-form solutions for gain saturation due to input signal and ASE flux axe also given. More complicated gain functions, such as inclusion of reabsorption in dye lasers, are also treated in some detail.

Comparison of prism-expander and grazing-incidence grating cavities for copper laser pumped dye lasers

Operating characteristics of a variety of rhodamine 590 dye laser oscillators transversely pumped by a pulsed copper bromide laser at low repetition rates are reported and compared. The cavities investigated include simple prism-expander and grazing-incidence grating arrangements as well as double-prism and prism preexpanded grazing-incidence grating configurations. Linewidths of ~0.01 A at energy conversion efficiencies up to 10% were obtained for a prism preexpanded grazing-incidence grating cavity with good beam quality and low background superluminescence (<0.01%).

High power narrowband pulsed dye laser oscillator-amplifier-system

Construction details and operating characteristics are reported for a pulsed dye laser oscillator followed by a three-stage dye laser amplifier. The system is excited with 220 m J of the second or120 m J of the third harmonic radiation of a Nd-YAG laser. With Rhodamine dyes the output energy exceeds 55 m J (9 MW peak power). Coumarin dyes provide pulses of more than 15 m J (3 MW). Spectral narrowing to less than 260 MHz or 2.7 × 10 -4 nm at 565 nm is achieved by a single intracavity etalon of 37.5 GHz free spectral range. Gas pressure tuning allows a continuous linear variation of the laser frequency over more than 3.9 × 10 3 GHz (4 nm at 565 nm). The frequency doubled laser output provides tunable UV light of narrow bandwidth (1.4 × 10 -4 nm) and of peak powers exceeding 3 MW.

A double-channel nitrogen laser

A compact double-channel nitrogen laser which permits the simultaneous pumping of two dye lasers, or a dye laser oscillator and a dye amplifier, is described. The characteristics of each emitted pulse are typically 200 kW and 5 ns.

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This paper reports simple coaxial flashlamp-excited dye lasers developed and fabricated high power, frequency tunable light sources for use in a variety of spectroscopy and optical instrumentation systems such as laser radars and remote sensors. Optimum design parameters of the discharge tube length and the annular width are obtained. The operational performances used as a dye laser oscillator and an amplifier are investigated using Rhodamine 6G in ethanol and pure water-Ammonyx LO solvents. In the oscillator mode of operation, maximum output energy of about 400 mJ and energy conversion efficiency of 0.12% are realized. In the amplifier mode, effective output gain of 120 is measured and a stable synchronization of the flashlamp discharge with the oscillator laser is attained by utilizing simmer discharge technique. Higher pulse repetition rate and smaller laser beam divergence are possible by using pure water as a dye solvent than ethanol. No remarkable output degradation of the coaxial flashlamp is observed in excess of 1000 shots at 300J input energy.

A regenerative power amplifier operating on the blue-green line of the nitrogen ion laser

Operation of the nitrogen ion laser as an optical regenerative amplifier driven by a master oscillator allows the output to be effectively switched into the blue-green region of the spectrum. In this work an amplifier containing a dilute plasma of nitrogen ions was pumped by thermolecular charge transfer from He2+ produced by an intense e-beam propagating through several atmospheres pressure of gas mixture. The injection of relatively broadband output from a dye laser oscillator caused the output from the amplifier to switch entirely into the (0,2) vibrational component of the B→X electronic transition of N+2 at 470.9 nm. An output linewidth of 0.007 nm was achieved together with the early saturation of the laser transition needed for the extraction of power from the amplifier at optimal efficiency.

Powerful dye laser oscillator-amplifier system for high resolution and coherent pulse spectroscopy

A peak power output of 100 kW in the visible at a linewidth as low as 60 MHz has been generated by using a cw dye laser oscillator followed by three single pass dye amplifier stages (or one double pass stage and one single pass stage), pumped by a single 1 MW nitrogen laser. The very high output power obtained in this laser system may be used to produce coherent ultraviolet pulses by sum or second harmonic generation in non-linear crystals or by third order mixing in atomic vapor.

Pulsed Narrow-band Dye Lasers

Construction and performance characteristics of organic dye lasers, pumped by high power pulsed gas or solid-state lasers, are discussed by reviewing several recently reported dye laser oscillator and oscillator amplifier systems. For spectroscopic applications pulsed lasers are compared to CW lasers and conventional light sources.

Powerful dye laser oscillator-amplifier system for high resolution spectroscopy

Peak powers of 50 kW in the visible at line widths down to 6 × 10 -4 Å can be generated with a gas-pressure tuned, dye laser oscillator with external filter interferometer, followed by a two-stage dye laser amplifier, pumped by one 1 MW nitrogen laser. Frequency doubling in lithium formate monohydrate permits high resolution, uv fluorescence spectroscopy down to 2300 Å, as demonstrated in Hg and C 6H 6. The system has also been used successfully for high-resolution two-photon spectroscopy of C 6H 6.

Graded-gain dye laser amplifiers: an experimental investigation

The influence of inhomogeneous distributions of gain and refractive index produced by the pumping radiationon the performance of dye laser amplifiers is discussed. Experimental measurements in capillary cylindrical cells and planar cells are reported for single-pass, double-pass, and ring configurations. Gain factors up to 8.5 x 10(4) have been obtained at low signal input with rhodamine 6G in ethanol. A saturated gain of 5 x 10(3) at 100-mJ output with an over-all efficiency of 0.1% has been achieved without full optimizationof the amplifier parameters. The reported results indicate that a two-stage double-pass amplifier driven by a dye laser oscillator in the milliwatt region can be used as an efficient high energy light source.