IRVINE, Calif., June 6, 2011 — For multimodal imaging and spectroscopy applications, Newport Corp. has introduced the WEU-02 wavelength extension unit, designed to expand the capability of femtosecond lasers. Through a series of user controls, the device can be configured for use in various spectroscopy, imaging and pump-probe applications, and it can be integrated into two-photon microscope setups to add modalities for enhanced imaging. Its design allows the fundamental beam to pass through, preserving the beam path and tuning range of the pump source. A portion of the fundamental beam can be sent to a photonic crystal fiber to be converted to a broadband supercontinuum. This light can then be recombined with the remaining fundamental for use in pump-probe and multimodal spectroscopy and microscopy experiments. The supercontinuum can be used as a Stokes beam to add broadband coherent anti-Stokes Raman scattering spectroscopy and microscopy capabilities around 3000 cm-1 in existing setups using two-photon excited fluorescence and second-harmonic generation. A thumbwheel either maintains the fundamental for two-photon imaging or selectively splits it to add pump-probe and multimodal capability. Thumbwheels also are used to independently control the attenuation of the fundamental beam, the input to the photonic crystal fiber and the output Stokes beams. Two-position slide controls allow the user to narrow the bandwidth to 3 nm around an 800-nm pump, or to select whether or not to recombine the pump and Stokes. A micrometer is used to fine-tune the timing of the two beams to overlap them temporally.