Direct electric-field reconstruction of few-cycle mid-infrared pulses in the nanojoule energy range

Abstract

Amid the increasing potential of ultrafast mid-infrared (mid-IR) laser sources based on transition metal doped chalcogenides such as Cr:ZnS, Cr:ZnSe, and Fe:ZnSe lasers, there is a need for direct and sensitive characterization of mid-IR mode-locked laser pulses that work in the nanojoule energy range. We developed a two-dimensional spectral shearing interferometry (2DSI) setup to successfully demonstrate the direct electric-field reconstruction of Cr:ZnS mode-locked laser pulses with a central wavelength of 2.3 µm, temporal duration of 30.3 fs, and energies of 3 nJ. The reconstructed electric field is in reasonable agreement with an independently measured intensity autocorrelation trace, and the quantitative reliability of the 2DSI measurement is verified from a material dispersion evaluation. The presented implementation of 2DSI, including a choice of nonlinear crystal as well as the use of high-throughput dispersive elements and a high signal-to-noise ratio near-IR spectrometer, would benefit future development of ultrafast mid-IR lasers and their applications.

Optical manipulation of electron emission at metal-insulator interface for all-solid-state light phase detector

“…We measure the photocurrent by illuminating the device with a mode-locked Cr 2+ :ZnS laser (2.3 µm, 40 MHz, 50 fs) 5,6 . Figure 4 displays the intensity dependence of the measured photocurrents for the hybrid DP (red), hybrid GP (blue), and bare DP (black) structures.…”

All-Solid-State Optical-Field-Sensitive Detector for Sub-Nanojoule Pulses Using Metal–Insulator Hybrid Nanostructure

“…We fabricate these nanoantenna devices using the electron beam lithography technique. , For the hybrid devices, we further sputter the Al 2 O 3 and Au layers (see Supporting Information for details). The photocurrent measurements are performed with a mode-locked Cr 2+ :ZnS laser, , emitting approximately 50 fs pulses with a center wavelength of 2.3 μm at a repetition rate of 40 MHz. The laser pulses are focused by an f = 15 mm parabolic mirror to a spot with a diameter of 20 μm.…”