Related Experiment Video
Updated: Jul 7, 2026

Femtosecond Laser Filaments for Use in Sub-Diffraction-Limited Imaging and Remote Sensing
Published on: April 25, 2019
Broadly tunable femtosecond pulse generation in the near and mid-infrared
Abstract:
High-repetition-rate (80-MHz) femtosecond infrared pulses are generated by difference frequency mixing (DFM) a femtosecond Ti:sapphire laser with a phase-locked synchronized cw mode-locked Nd:YAG picosecond laser. This DFM scheme is of particular interest for generating ultrashort near-IR pulses (~10 fs) because group velocity mismatch with a pump pulse can be ignored. The simplicity and the broad wavelength tunability (from the near IR to the mid-IR) of this scheme is demonstrated. Short (125-fs FWHM) optical pulses in the near IR around 1.5 mum are obtained with noncritical type-I phase-matched LiB(3) O(5). We also used a similar scheme to generate mid-infrared pulses at 3.0 mum with type-II phase-matched KTiOPO(4).
Related Concept Videos
IR Frequency Region: Fingerprint Region
The...
Infrared (IR) Spectroscopy: Overview
Different compounds display unique properties due to their...
IR Frequency Region: X–H Stretching
NMR Spectrometers: Radiofrequency Pulses and Pulse Sequences
IR Spectroscopy: Molecular Vibration Overview
Stretching vibrations are vibrational motions that occur along the bond line, changing the bond length or distance between two bonded atoms. They are further distinguished as symmetric or asymmetric. In symmetric stretching, the...
IR Absorption Frequency: Hybridization
Among the sp, sp2, and sp3 hybridized orbitals, sp orbitals have the maximum s character (50%). Consequently, the electrons are held more closely to the nucleus, resulting in stronger and shorter C–H bonds that stretch at a...

