Modified Šolc notch filter for deep ultraviolet applications.

We present results of the design and testing of a modified optical Šolc notch filter for use in the deep ultraviolet (DUV, 190-300 nm) spectral range. The filter was designed to block a specific wavelength in this region. In addition, a sequence of blocked wavelengths occurs at wavelengths both shorter and longer than the specified wavelength. For Raman applications utilizing tunable lasers, the provision of multiple blocked wavelengths by a single filter may be especially useful. The filter design presented here produces extinction ratios >240 with transmission minima ~1 nm full width at half-maximum. Specific results are shown for the Raman spectra of Teflon excited at 248.4 nm.