We demonstrate an intracavity absorption spectroscopy system based on a broadband single-crystal pulsed Fe:ZnSe laser. The laser operates at room-temperature and is continuously tunable in the spectral range of 3.76–5.29 µm. The long-wavelength emission up to 5.29 µm is a record achievement for Fe:ZnSe lasers, to the best of our knowledge. The developed laser system is applied for measurements of gaseous absorption inside the laser resonator. We demonstrate sensitive detection of (i) CO₂ isotopes in the atmosphere and in human breath, (ii) CO in breath (after cigarette smoking) and in the smoke of a smoldering paper, and (iii) N₂O in a gas flow. The achieved detection limits are: 0.1 ppm for ¹²CO₂ and ¹³CO₂, 3 ppm for CO, and 1 ppm for N₂O. The sensitivity of the current system is primarily limited by the short pump-pulse duration of 40 ns. Possibilities for sensitivity enhancement by up to a factor of 10⁷ are discussed.

We report for the first time to the best of our knowledge on the ultra-short pulse (USP) generation in the dispersion-managed erbium-doped all-fiber ring laser hybridly mode-locked with boron nitride-doped single-walled carbon nanotubes in the co-action with a nonlinear polarization evolution in the ring cavity with a distributed polarizer. Stable 92.6 fs dechirped pulses were obtained via precise polarization state adjustment at a central wavelength of 1560 nm with 11.2 mW average output power, corresponding to the 2.9 kW maximum peak power. We have also observed the laser switching from a USP generation regime to a chirped pulse one with a corresponding pulse-width of 7.1 ps at the same intracavity dispersion.

We report a laser operation from a Fe:CdTe single crystal, pumped by 40-ns pulses of a 4.12-µm Fe:ZnSe laser. The maximum output energy of 5.8 mJ was produced at 5.4 µm with 30% absorbed energy slope efficiency. A record 2300-nm-wide smooth and continuous wavelength tunability over 4.5-6.8 µm range was demonstrated, being the longest wavelength tuning achieved for Fe²⁺-doped chalcogenide lasers. We also discuss the features of the oscillation spectra.

We report on ultra-short stretched pulse generation in an all-fiber erbium-doped ring laser with a highly-nonlinear germanosilicate fiber inside the resonator with a slightly positive net-cavity group velocity dispersion (GVD). Stable 84 fs pulses were obtained with a 12 MHz repetition rate at a central wavelength of 1560 nm with a 48.1 nm spectral pulse width (full width at half maximum, FWHM) and 30 mW average output power; this corresponds to the 29.7 kW maximum peak power and 2.5 nJ pulse energy obtained immediately from the oscillator.

In high purity C e 3 + -doped selenide glass pumped by a 4.08 µm Fe:ZnSe laser, 5.1–5.5 µm laser oscillations were observed. This is the first evidence of laser action corresponding to the 2 F 7 / 2 → 2 F 5 / 2 transition of C e 3 + ions.

An extensive study of a novel room-temperature mid-infrared Ce³⁺-doped Ge₂₀Sb₁₀Ga₅Se₆₅ glass laser is reported. An influence of output-coupler transmission on laser efficiency and emission spectra is investigated. Pumped by a pulsed Fe:ZnSe laser at 4.1 µm, a maximum output energy of 35 mJ is demonstrated at 5.2 µm, with a laser threshold of about 60 mJ and a slope efficiency of 21%. The tuning range of a mid-infrared Ce:glass laser is reported for the first time: with an intracavity prism, the laser is continuously tunable in the spectral range of 4.5–5.6 µm. The internal losses are determined to be below 9% per roundtrip.