Alpine Research Optics (Boulder, CO) has released a Spectral Shaping Filter providing a route to shorter pulses from titanium:sapphire amplifiers. This intra-cavity optic is a dielectric coated filter with a spectral transmission curve designed to compensate for spectral narrowing due to gain flattening. The optic is available in 1" and 2" diameters. Both the center wavelength and the magnitude of the single-pass gain correction can be adjusted with the filter. Varying the angle of incidence at which the optic is mounted causes a shift in the center wavelength. This enables the filter’s performance to be matched to the skewed spectral gain curve of chirped amplifiers. By rotating the filter angle relative to the beam polarization, its transmission maximum can be increased or decreased, allowing the same filter to be used in both a multi-pass or regenerative-type amplifier.


Topics:
Photonics