定义：
与超快现象相关的光学

超快光学是与超快现象相关的光学，这些现象发生在皮秒甚至更短的时间尺度内。通常情况下，超快光学实验所涉及的超短脉冲是由锁模激光器产生（参阅超快激光物理）。 
超快现象过程由于其反生过程很短因此很难通过电学的方法直接观测，因此需要诸如泵浦探测测量等方式进行测量。通过这些技术就可以对皮秒或飞秒的时间尺度发生的现象进行监控。这些现象包括：电子的飞秒动力学（特别是在固体如半导体器件SESAMS中），光诱导相变（如金属的融化或汽化），化学反应等。 
目前，超快光学正扩展到亚飞秒领域中，在这一领域可以通过高强度的超短脉冲进行高次谐波产生阿秒脉冲（或脉冲串）。

Definition: the part of optics dealing with ultrafast phenomena

More general term: optics

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 for 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 for 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.