We present a new variant of spectral-shearing interferometry method for characterizing ultrashort laser pulses. This original approach, called Doppler Effect E-field Replication (DEER), exploits the rotational Doppler effect for producing the frequency shear and provides a spectral-shearing in the absence of frequency conversion enabling operation in the ultraviolet spectral range. Evaluation of the DEER-SPIDER setup reveals a phase reconstruction of great reliability. Possible improvements, benefits, and worthwhile prospects of the method are discussed.

A simple and compact single-shot autocorrelator is presented and analyzed in detail. The autocorrelator is composed of two elements only: a Fresnel biprism used to create two temporally delayed replicas of the pulse to characterize and a camera in which two-photon absorption takes place. The two-photon absorption signal obtained in the camera can be used to retrieve the pulse duration, the frequency chirp, and the pulse spectrum, provided that a Gaussian temporal shape is assumed. Thanks to its extreme simplicity, the autocorrelator is robust and easy to align. The presented design can theoretically characterize the pulse duration from about 25 fs to 1.5 ps in the two-photon spectral range of the camera (1200-2400 nm). Finally, a proof-of-principle demonstration is also performed at 3.1 µm by using an InGaAs camera, whose two-photon spectral range is located further in the infrared (1800-3400 nm).

Technological advances in femtosecond laser sources call for the development of increasingly refined characterization tools implying to enrich the existing panel of operable nonlinear interactions. Toward that end, we have recently proposed a variant of SPIDER (spectral phase interferometry for direct electric field reconstruction) based on a nonstandard effect for producing the frequency shear, the so-called rotational Doppler effect. The method called DEER-SPIDER, for Doppler effect E-field replication, has the advantage of producing a spectral shearing at/near the fundamental wavelength, thus allowing operation in the ultraviolet spectral range. The present paper provides a deeper study of this approach. The method is tested under two different challenging conditions, and a thorough theoretical analysis is proposed. Possible improvements and an outlook are also discussed.