Electronically tuned diode-laser-pumped Cr:LiSrA1F(6) laser

Chromium-doped LiCAF laser passively Q switched with a V3+:YAG crystal

A tunable, lamp-pumped Cr3+:LiCaAlF6 laser that operates in the 760-800-nm wavelength range is demonstrated. As a passive Q switch the V3+:YAG crystal, characterized by wide saturable absorption in the 760-900-nm wavelength range, was applied. The V3+:YAG parameters were determined by spectroscopic and saturable transmission measurements. The 30-mJ output energy at 2-Hz repetition rate in the free-running regime was obtained in a cavity reinforced by a diaphragm near the fundamental mode. The dispersive prism inserted into the cavity enabled tuning in the 760-800-nm wavelength range. In the passive Q-switching regime we achieved greater than 1-mJ energy with 50-ns pulse duration in a 35-cm-long cavity. A numerical model that takes into account the short recovery time of V3+:YAG (approximately 5 ns) and excited-state absorption was used to analyze such a laser.

Widely Tunable Continuous-Wave CR(3+):LiSrAlF(6) Ring Laser from 800 to 936 nm

We report on a widely tunable, diode-pumped, continuous-wave, single-frequency Cr(3+):LiSrAlF(6) laser with a novel double-ring cavity configuration. The optical diode and the tuning element were located in the ring subcavity to decrease their insertion loss. Using an 1800-lines/mm grating as the tuning element, we obtained a laser emission of 20-mW output power at 870 nm and a tuning range of from 800 to 936 nm. When we used a 1200-lines/mm grating with a higher diffraction efficiency, the laser had a slightly wider tuning range of from 800 to 938 nm. However, the output power decreased at this tuning range.

Single-mode cw Cr(3+):LiSrAlF(6) laser using an external fiber grating

A Cr(3+):LiSAF laser oscillator self-injection locked by an externally coupled fiber grating was constructed. Single-mode operation in a Cr(3+):LiSAF laser was obtained by use of a 67%-ref lectivity fiber grating that was fabricated with a holographic technique in which a narrow-band KrF UV laser exposure was used. This configuration permits the use of a fiber grating with optimum ref lectivity for efficient single-mode operation.

Electronically tuned Ti:sapphire laser

We have applied a birefringent acousto-optic crystal for wavelength tuning of a Ti:sapphire laser. A continuous-tuning range of 12 nm, which was limited by wavelength-dependent angle deviation of the beam def lection in the crystal, was extended to over 100 nm by optical correction. Fast and random access of lasing wavelengths by direct electronic tuning was demonstrated at a pulsed operation of 10 Hz.

Single-mode continuous-wave Cr(3+):LiSAF ring laser pumped by an injection-locked 670-nm broad-area diode laser

We report on an efficient continuous-wave Cr(3+):LiSrAlF(6) ring laser pumped by the near-diffraction-limited output of an injection-locked 665-nm broad-area diode laser. With an absorbed pump power of 120 mW the ring laser generates 22 mW of single-mode 855-nm radiation with a spectral linewidth of less than 10 MHz. Unidirectional operation and longitudinal-mode control of this ring laser is achieved by injection of 855-nm diode-laser radiation into the ring cavity. Optical feedback of ring-laser radiation into the diode laser narrows the diode laser's linewidth and locks its frequency to a resonance of the ring resonator.

Properties of Cr:LiSrAIF(6) crystals for laser operation

We have performed several physical and optical measurements on the Cr:LiSAF (LiSrAlF(6)) laser material that are relevant to its laser performance, including thermal and mechanical properties, water durabilities, and Auger upconversion constants. The expansion coefficient, Young's modulus, fracture toughness, thermal conductivity, and heat capacity are all used to determine an overall thermomechanical figure of merit for the crystal. An investigation of the water durability suggests that the cooling solution should be maintained at pH = 7 to ameliorate problems associated with water dissolution. The Auger constant was found to become much more significant at higher Cr doping, in which excited-state migration leads to a substantial increase in the upconversion rate. We propose a design for a 50-W Cr:LiSAF laser system that is based on a detailed knowledge of all the relevant material parameters.

All-solid-state actively mode-locked Cr:LiSAF laser

We have demonstrated an actively mode-locked Cr:LiSAF laser pumped by 659-nm radiation from an intracavity frequency-doubled diode-pumped Nd:YLF laser. The laser was tunable from 815 to 915 nm, and pulses of 30-ps duration at an average power of 3.5 mW were generated. With further development this all-solid-state system will be particularly suitable for the production of femtosecond pulses, by the technique of Kerr-lens mode locking.

Terawatt Cr:LiSrAIF(6) laser system

We have developed a compact flash-lamp-pumped Cr:LiSrAlF(6) (Cr:LiSAF) laser system capable of producing peak powers in excess of 1 TW. Chirped-pulse amplification in a Cr:LiSAF regenerative amplifier produces 8-mJ pulses at a 5-Hz repetition rate. Further amplification in Cr:LiSAF yields recompressed pulse energies of 150 mJ and a pulse duration <135 fs at a 0.5-Hz repetition rate.