V. P. Mitrokhin

Laser ablation of dental tissues with picosecond pulses of 1.06-μm radiation transmitted through a hollow-core photonic-crystal fiber

Sequences of picosecond pulses of 1.06-microm Nd:YAG laser radiation with a total energy of approximately 2 mJ are transmitted through a hollow-core photonic-crystal fiber with a core diameter of approximately 14 microm and are focused onto a tooths surface in vitro to ablate dental tissue. The hollow-core photonic-crystal fiber is shown to support the single-fundamental-mode regime for 1.06-microm laser radiation, serving as a spatial filter and allowing the laser beams quality to be substantially improved. The same fiber is used to transmit emission from plasmas produced by laser pulses onto the tooths surface in the backward direction for detection and optical diagnostics.

Hollow-core photonic-crystal fibres for laser dentistry

Hollow-core photonic-crystal fibres (PCFs) for the delivery of high-fluence laser radiation capable of ablating tooth enamel are developed. Sequences of picosecond pulses of 1.06 microm Nd:YAG-laser radiation with a total energy of about 2 mJ are transmitted through a hollow-core photonic-crystal fibre with a core diameter of approximately 14 microm and are focused on a tooth surface in vitro to ablate dental tissue. The hollow-core PCF is shown to support the single-fundamental-mode regime for 1.06 microm laser radiation, serving as a spatial filter and allowing the laser beam quality to be substantially improved. The same fibre is used to transmit emission from plasmas produced by laser pulses on the tooth surface in the backward direction for detection and optical diagnostics.

Coherent anti-Stokes Raman scattering microspectroscopy of silicon components with a photonic-crystal fiber frequency shifter.

Coherent anti-Stokes Raman scattering (CARS) microspectroscopy of silicon components is demonstrated with pump and probe fields delivered by a mode-locked Cr:forsterite laser and the frequency-shifted soliton output of a photonic-crystal fiber as a Stokes field. CARS microspectroscopy is shown to allow a visualization of microscale features and defects on the surface of silicon wafers, offering much promise for online diagnostics of electronic and photonic silicon chip components.

Two-photon absorption-induced effects in femtosecond coherent anti-Stokes Raman-scattering microspectroscopy of silicon photonic components

We study the effects related to two-photon absorption (TPA) in the microspectroscopy of the silicon photonic components based on coherent anti-Stokes Raman scattering (CARS) of femtosecond pulses. With 300-fs pulses of 1.24-μm Cr:forsterite laser radiation delivering pump and probe fields and a frequency-shifted soliton output of a large-mode area photonic-crystal fiber employed as a Stokes field, pronounced TPA effects have been observed in the CARS microspectroscopy of silicon components for pump-pulse intensities exceeding 10 GW/cm2.