Mikhail K. Tarabrin

Visible supercontinuum generation in large-core photonic crystal fiber with high air-filling fraction

We demonstrate new experimental results for visible supercontinuum generation in large-core photonic crystal fiber with high air-filling fraction. Supercontinuum is generated by picosecond pulses from a passively mode-locked Yb:KGW laser. A smooth supercontinuum generation near 800 nm is achieved using 4.5 m long large-core photonic crystal fiber even with 6 mW average coupled power. These results are of interest in high power white light sources and have potential applications in precise frequency metrology and spectroscopy. The data obtained could be used also in theoretical studies of nonlinear interaction in large-core photonics crystal fibers with high air-filling fraction.

Stable Similariton Generation in an All-Fiber Hybrid Mode-Locked Ring Laser for Frequency Metrology

Ultrashort pulse lasers constitute an important tool in the emerging field of optical frequency metrology and are enabling unprecedented measurement capabilities and new applications in a wide range of fields, including precision spectroscopy, atomic clocks, ultracold gases, and molecular fingerprinting. We demonstrate the generation of stable 127-fs self-similar pulses at a central wavelength of 1560 nm with 7.14-mW average output power. Similariton lasers have a low repetition rate deviation in the averaging time interval 1-1·103 s, a low relative intensity noise -120 dBc/Hz (30 Hz to 10 kHz), a narrow single comb line width of 32 kHz, and high reliability. Thus, such lasers are highly promising for further development of the stabilized combs and open up a robust and substantially simplified route to synthesizing low-noise microwaves.

Tunable CW Solid-State Mid-IR Cr 2+ :CdSe Single Crystal Laser with Diode Laser Array Pumping

We demonstrate the first Cr2+:CdSe single crystal laser with diode laser array pumping. Laser efficiency of 12% with output power of 280 mW was obtained. Tunable CW operation was observed in 2450 - 3060 nm range.

Broadband tunable mid-IR Cr2+:CdSe lasers for medical applications

Currently, lasers are widely used for surgery, medical diagnostics and oncology research. Unfortunately, most of the used laser sources have a significant drawback - the lack of operating wavelength tuning possibility, which imposes significant limitations on the investigation of biological tissues spectral properties and searching for the optimal mode of their treatment. Comparison between different promising mid-IR sources was made. We report on development of mid-infrared (mid-IR) tunable lasers based on the Cr2+:CdSe single-crystals. These lasers operate in CW mode with the maximum output power of up to 2 W and possible tuning range from 2.2 to 3.6 μm.

1 Watt, 59 % slope efficiency, 2.65 pm Cr 2+ :CdSe laser with tenability of 560 nm

We report the highest slope efficiency from a Cr²⁺:CdSe laser. The sample was multilayered dielectric coated with TaO<inf>2</inf> and SiO<inf>2</inf> to achieve this performance. The output beam was a diffraction limited TEM<inf>00</inf> gaussian mode.

Fiber Bragg gratings strain measuring system and a sensor calibration setup based on mechanical nanomotion transducer

Fiber Bragg grating (FBG) strain sensors are powerful tools for structural health monitoring applications. However, FBG sensor fabrication and packaging processes can lead to a non-linear behavior, that affects the accuracy of the strain measurements. Here we present a novel nondestructive calibration technique for FBG strain sensors that use a mechanical nanomotion transducer. A customized calibration setup was designed based on dovetail-type slideways that were mechanized using a stepping motor. The performance of the FBG strain sensor was investigated through analysis of experimental data, and the calibration curves for the FBG strain sensor are presented.

Thermo-optical and lasing characteristics of Cr 2+ -doped CdSe single crystal as tunable coherent source in the mid-infrared

We report on a comprehensive characterization of Cr2+-doped CdSe single crystal as an efficient active material for tunable laser applications in the mid-infrared spectral region. Optical gain, thermo-optical behavior, power efficiency, scalability and wavelength tunability have been thoroughly investigated. Using an antireflection-coated crystal pumped by a Tm-fiber laser at at 1.94 μm, 1-W CW output power and 50% slope efficiency at 2.65 μm emission wavelength have been obtained in a diffraction-limited output beam. An output peak power of 2.5 W has been achieved without significant beam distortion in a quasi-CW regime. Exploiting an intra-cavity diffraction grating in a Littrow configuration, a maximum tuning range of 900 nm from 2.22 to 3.12 μm, limited by the finite bandwidth of resonator components, has been demonstrated with an uncoated crystal.

All-fiber hybridly mode-locked similariton ring laser for frequency metrology

We demonstrate the generation of stable 127 fs self-similar pulses at a central wavelength of 1560 nm with 7.14 mW average output power. Similariton lasers have low repetition rate deviation in the averaging time interval 1-1·103 s, a low relative intensity noise -125 dBc/Hz, a narrow single comb line width of 32 kHz, and high reliability. Thus, such lasers are highly promising for further development of the stabilized combs.

High-order modes supercontinuum generation in a large-core photonic crystal fiber

We report on experimental investigation spectral properties of high-order modes SC generation in a large-core photonic crystal fiber with high air-filling fraction. Optical properties of large-core photonic crystal fiber were analysed. The SC generation in high-order modes LP11, LP21 and LP02 were observed under different input conditions.