Ultrafast optically heterodyne detected transient grating spectroscopy using diffractive optics

Summary form only given.Optical heterodyne detection (OHD) is a well-established method for achieving both amplification and linearization of optical signals generated from nonlinear experiments by coherently mixing a large reference field with a signal field of interest. Since the heterodyne signal is the interference term between the signal and reference fields, it is necessary to keep their relative phase difference, /spl Delta//spl phi/, constant. We have implemented OHD in a transient grating (TG) experiment to achieve passive stabilization of /spl Delta//spl phi/ without the need for either active feedback loops or unusual mechanical stability. This stability arises from the geometric symmetry of the the TG phase matching condition coupled with the optical arrangement, which eliminates phase noise arising from small fluctuations of the optics.