No abstract

A single-shot measurement of terahertz electromagnetic pulses is implemented using two-dimensional electro-optic imaging with dual echelon optics. The reported embodiment produces sequentially delayed multiprobe beamlets, routinely providing a time window of >10 ps with ~25 fs temporal step sizes. Because of its simplicity and robustness, the technique is ideally suited for real-time ultrashort relativistic electron bunch characterization.

We present a single-shot, high-temporal-resolution terahertz diagnostic capable of measuring free-space far-infrared electromagnetic fields in time and space. We show that by using a chirped probe electro-optic sampling technique, in combination with a recently described interferometric retrieval algorithm [Appl. Phys. Lett. 87, 211109 (2005)], the diagnostic can provide transform-limited temporal resolution, mainly limited by the spectral bandwidth of the optical probe pulse, regardless of its chirp.

Z. P. Jiang and X. C. Zhang demonstrated a single-shot THz diagnostic based on spectral encoding of a chirped optical probe pulse [Appl. Phys. Lett. 72, 1945 (1998)]. This technique is thought to have an inherent uncertainty principle-imposed temporal resolution limitations. In this letter, we describe a method to recover the THz field without distortions, surpassing previous resolution limitations. Our approach is based on interpreting the spectral encoding experiment as in-line spectral interferometry, analogous to Gabor’s in-line spatial holography [D. Gabor, Nature (London) 161, 777 (1948)]. We recover the THz field from the interferogram and the characterized probe by using Tikhonov regularization combined with lower and upper triangular decomposition.