Measuring temporally complex ultrashort pulses using multiple-delay crossed-beam spectral interferometry

Abstract

We introduce a spectral-interferometry (SI) technique for measuring the complete intensity and phase of relatively long and very complex ultrashort pulses. Ordinarily, such a method would require a high-resolution spectrometer, but our method overcomes this need. It involves making multiple measurements using SI (in its SEA TADPOLE variation) at numerous delays, measuring many temporal pulselets within the pulse, and concatenating the resulting pulselets. Its spectral resolution is the inverse delay range--many times higher than that of the spectrometer used. Our simple proof-of-principle implementation of it provided 71 fs temporal resolution and a temporal range of 100 ps using a few-cm low-resolution spectrometer.

Interaction of ultrashort-laser pulses with induced undercritical plasmas in fused silica

“…Experimental measurements designed to measure the complete complex field as a function of space and time (see, e.g., the recent methods in Refs. [37][38][39][40][41]) will reduce the need to assumeg an initial field with no spatiotemporal dependences or to use apertured FROG traces. Additionally, recent investigations into the possible role of high-order nonlinear optical effects [42][43][44], ionization by multichromatic pulses [45], and the influence of phenomenological parameters (such as the free-carrier collision time and the effective electron mass) [46] may also allow for further improvements in predamage calculations.…”

Single-shot multiple-delay crossed-beam spectral interferometry for measuring extremely complex pulses

“…At the same time, this effort is also driving the field of optical metrology to develop new high-temporal-and high-spectral-resolution techniques [2][3][4][5][6][7][8] to measure such extremely complex waveforms.…”

“…In previous work, we demonstrated a multi-shot time-interleaving technique that we call MUD TADPOLE. It has the ability to measure pulses with extremely large TBPs, and we have used it to measure pulses with TBPs of 65,000 [8]. MUD TADPOLE is a simple temporal scanning version of SEA TADPOLE [18][19][20][21][22][23], which is an experimentally simplified variation of SI that involves crossing at an angle the pulse to be measured with the previously measured reference pulse, which greatly simplifies alignment.…”

“…Although the single-shot MUD TADPOLE retrieval algorithm is very similar to that of multi-shot MUD TADPOLE [8] there are a few differences, and for that reason, we give a detailed explanation.…”

“…We use a Fourier retrieval algorithm [8] to filter the signal term from the interferogram. To do this we first take a spatial Fourier transform of Eqs.…”