ultrafast optics
- ️Dr. Rüdiger Paschotta
- ️Fri Feb 07 2025
Author: the photonics expert (RP)
Definition: the part of optics dealing with ultrafast phenomena
More general term: optics
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DOI: 10.61835/yaq Cite the article: BibTex plain textHTML Link to this page! LinkedIn
Contents
The term “ultrafast optics” occurs with two different meanings, which are treated in the following sections.
Ultrafast Optics as a Field of Physics
Ultrafast optics is the part of optics dealing with ultrafast phenomena, i.e. phenomena which occur on a time scale of picoseconds or less. Typically, ultrafast optics experiments involve ultrashort pulses as generated with mode-locked lasers (→ ultrafast laser physics).
As ultrafast phenomena are too fast to be directly monitored with electronics, optical techniques, such as pump–probe measurements, are required. With such techniques, phenomena occurring on time scales of picoseconds or femtoseconds can be monitored. Examples of such phenomena are femtosecond dynamics of electrons (particularly in solids, e.g. in semiconductor devices such as SESAMs), light-induced phase changes (e.g. melting or vaporization of metals), chemical reactions, and processes in plasmas.
Currently, ultrafast optics is being extended into the sub-femtosecond region, where attosecond pulses (or pulse trains) are obtained, e.g. via high harmonic generation with intense ultrashort pulses.
Optical Elements for Ultrafast Optics
Ultrafast optics can also denote optical elements which are specifically made or optimized for use in the field of ultrafast optics. Usually, optical elements are optimized such that one can send ultrashort pulses through them while avoiding excessive detrimental effects e.g. of chromatic dispersion and/or optical nonlinearities, or providing a suitable amount e.g. of chromatic dispersion for manipulation of the pulses.
Some examples of ultrafast optics are discussed in the following:
- There are low-dispersion mirrors, where substantial temporal pulse broadening is avoided. On the other hand, there are special dispersive mirrors for applying some significant amount of chromatic dispersion, e.g. for the purpose of dispersion compensation in the laser resonator of a mode-locked laser.
- There are also optical component and arrangements for substantially larger amounts of chromatic dispersion, as used e.g. for pulse compression, possibly also for pulse stretching e.g. in the context of chirped-pulse amplification. Examples of such components are chirped volume Bragg gratings, optical setups involving one or more diffraction gratings (possibly combined with mirrors or prisms), and special optical fibers.
- Saturable absorbers, particularly often in the form of semiconductor saturable absorber mirrors (SESAMs) are often used for initiating and stabilizing passive mode locking of lasers.
- Some types of optical modulators, e.g. electro-optic modulators, can be used as pulse pickers.
- There are special optical fibers – frequently photonic crystal fibers – which are optimized for delivering ultrashort light pulses. For example, one can use hollow-core fibers to minimize nonlinear effects.
More to Learn
Suppliers
The RP Photonics Buyer's Guide contains 26 suppliers for ultrafast optics. Among them:
EKSMA OPTICS
Our Femtoline laser optics are tailored for applications with high power ultrashort laser pulses. This series includes low group delay dispersion (GDD) laser mirrors, broadband mirrors, high power laser mirrors and group velocity dispersion (GVD) compensation plates.
Shalom EO
Shalom EO offers a wide range of ultrafast optics for femtosecond lasers and ultrafast pulsed lasers, with both off-the-shelf and custom versions available. Our product portfolio includes:
- ultrafast mirrors: femtoline low GDD dielectric mirrors, ultrafast-enhanced silver mirrors, chirped mirrors, and chirped mirror pairs
- ultrafast nonlinear crystals: BBO crystals with a minimum thickness of 0.01 mm and LBO crystals
- high precision thin BK7 and UV-grade fused silica windows
- dispersion prisms made of BK7, UVFS, and SF11 and group delay compensators made from calcite.
Our ultrafast or femtoline laser optical components minimize dispersion, aberrations, and losses to maintain pulse qualities, spatial coherence, and beam-pointing stability, enabling you to achieve exceptional results in your experiments or other applications.
UltraFast Innovations
CAPELLA, the light field synthesizer from UltraFast Innovations (UFI®), is the first of its kind offered commercially. It enables the synthesis and sub-femtosecond control of super-octave light transients.
Moreover, UFI offers a wide range of optical components suitable for ultrafast optics, e.g., mirrors and spectral filters.
LASEROPTIK
LASEROPTIK designs and produces various kinds of dispersive coatings, including chirped mirrors and matched pairs of chirped mirrors, also all other kinds of coated optics for dispersion management like GTI mirrors. We use Ion Beam Sputtering (IBS) for highest quality and widely ranging dispersion measurement setups for precise characterization.
OPTOMAN
OPTOMAN designs and manufactures application-optimized ultrafast optics: dispersive mirrors (chirped and GTI design) and low GDD ultrafast mirrors. OPTOMAN focuses exclusively on IBS technology, which allows to sputter coatings that exhibit excellent resistance to laser irradiation and meet cutting edge spectral requirements.
Standard in-stock IBS coated ultrafast optics can be found in OPTOSHOP.
Edmund Optics
Edmund Optics provides a breadth of ultrafast optics, including low GDD ultrafast mirrors, highly dispersive ultrafast mirrors, compression prisms, reflective objectives and beam expanders, and nonlinear crystals. These products are designed for common femtosecond lasers, including Ti:sapphire, Yb:doped fiber, thulium (Tm), and holmium (Ho).
Optogama
Low GDD ultrafast mirrors from Optogama exhibit high reflectance with minimal group delay dispersion (GDD) in a certain range of wavelengths and angles of incidence. These mirrors eliminate ultrashort optical pulse broadening effects and maintain high peak power as compared to ordinary high reflectivity laser mirrors. Our low GDD ultrafast mirrors are suitable for Ti:sapphire, Nd:glass or ytterbium-doped host based femtosecond lasers.
Thorlabs
Thorlabs manufactures a wide range of ultrafast optics specifically designed for ultrafast applications, including mirrors with a specialized coating optimized for use with femtosecond Ti:sapphire lasers, low-GDD beamsplitters and mirrors, nonlinear crystals, and chirped mirrors. To precisely characterize the dispersion of ultrafast optics over the 500 – 1650 nm range, consider Thorlabs’ Chromatis™ dispersion measurement system with the InGaAs detector add-on option.
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