Ultrafast mid-infrared laser systems and broad-band precision molecular spectroscopy

Date: Nov 13, 2019
Time: 02:00 PM (Local Time Germany)
Speaker: Prof. Dr. Gianluca Galzerano
Istituto di Fotonica e Nanotecnologie - Consiglio Nazionale delle Ricerche, and Dipartimento di Fisica - Politecnico di Milano
Location: Max-Planck-Institut für Quantenoptik
Room: Herbert Walther Lecture Hall

Femtosecond laser sources operating in the near- and middle-infrared (mid-IR) spectral range with high- repetition rates are of upmost interest for a variety of applications ranging from ultrafast spectroscopy, high-resolution and broadband spectroscopy, quantum optics, frequency metrology and synthesis of mid-IR optical frequency combs.

We present two different laser architectures to generate femtosecond pulse trains in the wavelength region from 2 to 3 μm useful for the synthesis of mid-IR optical frequency combs: a bulk laser system based on a Kerr-lens mode-locked (KLM) Cr²⁺-doped ZnSe crystal able to sustain four-optical-cycle pulse trains at 2.4 μm with repetition frequencies higher than 150 MHz and an all-fiber laser system based on a non-linear polarization evolution (NPE) mode-locked Dy-doped fluoride fiber that generates stable and self- starting pulses with a duration of 828 fs at 3.1 μm.

Moreover, based on commercially available near-IR fiber laser frequency combs, high-precision and broad band spectroscopy investigations of fluoroform (CHF₃) and acetylene (C₂H₂) molecules at around 8.6 and 1.55 µm, respectively, will be also presented.