定义：
锁模激光器或者调Q激光器等激光器每秒输出的脉冲数。简称：PRF

脉冲的重复频率frep指的是每秒的脉冲数量，也就是脉冲间隔时间的倒数。 

不同产生方式的脉冲串的重复频率差别很大，主要的脉冲产生方式以及对应的重复频率如下：

• 典型的固体锁模激光器的重复频率通常在50MHz到数GHz，也有少数情况能到10MHz以下或者高达百GHz；
• 固体的调Q锁模激光器的重复频率可以从小于1Hz到百kHz；
• 增益开光的半导体激光器的重复频率可以从小于1 Hz到数MHz。
• 利用高次谐波产生的有限长度阿秒脉冲序列的重复频率可以高达数百THz。 

如果脉冲串是规则的，并且脉冲之间是相干的，在频谱（或光谱）上其就为频率梳，而频率梳的梳齿间隔就是重复频率。 
相对于理想的周期性的脉冲序列的抖动则被称为时序抖动。

Acronym: PRF

Definition: the number of pulses emitted per second e.g. by a mode-locked or Q-switched laser

Alternative term: pulse repetition frequency

Formula symbol: f_rep

Units: Hz

The pulse repetition rate (or pulse repetition frequency) f_rep of a regular train of pulses is defined as the number of emitted pulses per second, or more precisely the inverse temporal pulse spacing.

Depending on the technique of pulse generation (concerning light pulses), typical pulse repetition rates can be in different parameter regions:

• Typical mode-locked solid-state lasers emit with pulse repetition rates between 50 MHz and a few gigahertz, but in extreme cases < 10 MHz or > 100 GHz are possible. In most cases, there is a single pulse circulating in such a laser, so that the pulse repetition rate is the inverse round-trip time in the laser resonator.
• Q switching of solid-state lasers typically allows repetition rates from below 1 Hz to the order of 100 kHz. For active Q switching, the pulse repetition rate is determined by an external drive signal, while for passive Q switching its depends on the magnitude of loss modulation, the pump power and various other parameters.
• Gain switching of semiconductor lasers can provide repetition rates from below 1 Hz to many megahertz.
• Attosecond pulse trains of finite length can be generated via high harmonic generation with repetition rates of hundreds of terahertz. Here, the pulse repetition rate is twice the optical frequency of the pump light.

The article on pulse trains for methods of multiplying or dividing the pulse repetition rate.

For burst mode lasers, there are two different repetition rates: the pulse repetition rate within each burst and the much lower repetition rate of the bursts.

If a pulse train is regular and the pulses are mutually coherent, the optical spectrum of the pulse train is a frequency comb, where the spacing of the lines is determined by the pulse repetition rate.

The deviation from perfect periodicity of the optical power is called timing jitter.