Ultrafast optical filters and beamsplitters

Newport Corporation has added two series to its family of ultrafast optics. The first new product family is circular variable neutral density (ND) filters with a metallic coating on a 2mm substrate, and the second is low group velocity dispersion (GVD) 50\50 ultrafast beamsplitters for P-polarised light. 

Newport's circular variable neutral density filters are designed to attenuate the wide spectrum of low energy laser light from UV to near IR wavelength. Their optical density gradient varies from 0–1.0, 0-2.0 and 0-4.0 around a by simply rotating the filter from 0 to 360°. Fused silica substrate for these ND filters allows the transparency from 200 to 2,000nm. The linear change in optical density is achieved by a fine Inconel coating that allows the controlled linear attenuation of light beam in the designated optical density range for wide spectrum of light. The second surface of this filter is coated with a broadband visible antireflection coating to minimise the reflective loss from the second surface.

Newport's low GVD 50/50 beamsplitters are designed to minimise pulse dispersion of reflected and transmitted ultrafast laser pulses. The front surface of the beamsplitter designed for S-polarised light is coated to provide a 50/50 split at 45° angle of incidence from 700 to 950nm, and the back surface is antireflection coated. The beamsplitter for the P-Polarised light is coated to provide a 50/50 split at 45° angle of incidence from 680 to 1,060nm. The UB.4 beamsplitters can be used to split the P-polarised output beam from ultrafast lasers and amplifiers such as the company's Spectra-Physics Solstice one-box ultrafast amplifier, Spitfire Pro ultrafast amplifier, and the Mai Tai family of ultrafast lasers.