Infrared photosensitivity in silica glasses exposed to femtosecond laser pulses

Abstract

We investigate the use of infrared femtosecond laser pulses to induce highly localized refractive-index changes in fused-silica glasses. We characterize the magnitude of the change as a function of exposure and measure index changes as large as 3x10(-3) and 5x10(-3) in pure fused silica and boron-doped silica, respectively. The potential of this technique for writing three-dimensional photonic structures in bulk glasses is demonstrated by the fabrication of a Y coupler within a sample of pure fused silica.

Femtosecond laser microstructuring: an enabling tool for optofluidic lab‐on‐chips

“…Since the heat diffusion time out of the absorption volume in glass can be estimated at 1 μs, the transition between the two regimes takes place at frequencies around 1 MHz. Low-frequency systems typically use regeneratively amplified Ti:sapphire lasers (1-200 kHz repetition rate) [26,47,48]. The high-frequency regime was initially accessed using Ti:sapphire oscillators with the cavity length stretched by a telescope or a multipass cell (5-20-MHz repetition rate) [49][50][51][52].…”

Femtosecond Fabrication of Waveguides in Ion-Doped Laser Crystals

“…Velocity of the translation in dependency of laser rep rate may be in the range of 0.01 -50 mm/s. Under moderate pulse energy, suitable for waveguide fabrication, PRICE is positive in fused silica and most of glasses (Davis, 1996;Miura, 1997;Homoelle, 1999;Schaffer, 2001;Streltsov, 2001). Thus even a single track recorded in glass is a waveguide core, while surrounding area is a cladding (Fig.1a).…”

Memory in Nonlinear Ionization of Transparent Solids

“…The modified nonlinear threshold could arise from this modification, or from the many defects that are almost certainly generated by this process. Like the memory effect, both the refractive index changes and the changes in Raman response are known to show saturation with exposure [18,19].…”