Vladimir M. Paramonov

Laser-diode-pumped phosphosilicate-fiber Raman laser with an output power of 1 W at 1.48 mum.

An all-fiber 1.48-mum generator based on a laser-diode-pumped Yb-doped double-clad laser and a cascaded Raman wavelength converter has been developed. Second-order Raman Stokes radiation was generated in a phosphosilicate-fiber resonator formed by two pairs of Bragg gratings. A slope efficiency of the Raman converter of 48% with respect to the power emitted by the double-clad Yb laser has been achieved. We obtained an output power of 1 W at a slope efficiency of 34% with respect to the laser-diode array power, with a total optical-to-optical efficiency of 23%.

Raman fiber laser for the drug-free photodynamic therapy

An SRS laser with a radiation wavelength of 1.262 μm and a maximum power of 5.5 W is presented. The laser wavelength corresponds to the excitation band of singlet oxygen and can be used for the treatment of oncological diseases. The laser source is employed for the treatment of basalioma.

Experimental and numerical optimization of a fiber Raman laser

We present an experimental test of a recently published model that describes a nested fiber Raman cavity taking into account all interactions between forward and backward traveling waves. The experiment consists in the realization of a one-stage fiber Raman laser, pumped at 1090 nm, using one Stokes shift to produce output radiation at 1150 nm. The conversion efficiency measured as a function of input power and fiber length is successfully compared with the numerical results. We also apply the model to the comparison between the performance of phosphosilicate (PS) and germanosilicate (GS) fibers. We have considered a five-step Raman laser using a GS fiber with a 1117 nm pump, and a two-step Raman laser using a PS fiber with a 1061 nm pump, both emitting at 1480 nm. In the optimum configuration, the simpler PS fiber laser presents a conversion efficiency about 15% lower than that of the GS fiber laser and uses a fiber length 40% larger.

Yb3+-doped double-clad fibers and lasers

We present results of the research and development of double-clad Yb3+-doped fibers for high-power fiber lasers. The quality of the fabricated fibers and optimization of reflecting Bragg gratings allowed us to demonstrate fiber lasers with a quantum efficiency close to 90%. These fiber lasers were used in Raman converters emitting at various wavelengths.

CW highly efficient 1.24 /spl mu/m Raman laser based on low-loss phosphosilicate fiber

We report the first demonstration of an extremely simple and efficient 1.24 /spl mu/m phosphosilicate fiber-based Raman laser with Bragg gratings written directly in the fiber used. The laser pumped by Nd fiber laser exhibits a slope efficiency of 80%.

Record-peak-power all-fiber single-frequency 1550 nm laser

In this paper, we present results on the amplification of 2 MHz linewidth nanosecond pulses in a recently developed ytterbium-free erbium-doped large mode area fiber cladding pumped at 980 nm. A record peak power of 4 kW for single-frequency single-mode silica-based fiber sources near 1550 nm is demonstrated. Pulse instabilities arising in an all-fiber laser scheme from stimulated Brillouin scattering are described.

Fiber Raman laser at 1450 nm for medical applications

Raman-fiber source emitting 1450 nm with a power of 1 W was realized. The application of the commercially available pump source with an output power of 35 W allows one to increase the output power up to 5 W. The emission wavelength corresponds to the water absorption band therefore it is promising laser for the surgery and other medical applications.

Efficient Yb fiber laser at 980 nm pumped by the high-brightness semiconductor source

Summary form only given. The present work deals with the fabrication of a special active fibers and Yb-doped fiber laser pumped by Superfocus to get an efficient high power oscillation in the vicinity of 980 nm. To build the fiber laser we have used the fiber with an all-silica inner cladding with NA of 0.22 and 25 /spl mu/m diameter and a core with a 6 /spl mu/m diameter. The laser cavity was formed by two gratings with reflection of 99% and 70% for input and output coupler respectively. To minimize the intracavity losses, Bragg gratings were written in the H/sub 2/-loaded active fiber without any splices inside the laser cavity.

High-power Yb-doped double-clad fiber lasers for a range of 0.98-1.04 µm

We have realized the set of Yb-doped double-clad fiber lasers operating around the Ybions fluorescence maximums. To get an efficient laser operation we have used the all-silica double-clad active fiber and high brightness semiconductor source.

1.43-μm fiber laser for medical applications

A 1.43 micrometers fiber laser with an output power of 1.4 W is reported. The laser is based on Raman conversion of the Yb- fiber laser emission in a phosphorous doped fiber. The light conversion is based on both phosphorous and silica Raman shifts in the same P-doped fiber. This device can find medical applications, since its emission wavelength coincides with one of the water absorption bands.