What are Femtosecond Lasers?

A femtosecond laser is a type of laser that emits laser pulses with a pulse duration in the femtoseconds (10 ^-15 seconds) range. Femtosecond solid-state lasers use a neodymium-doped gain medium or ytterbium-doped gain medium with laser diode pumping. The generation of such short light pulses is usually achieved with the technique of passive mode-locking. The high peak power and short pulse duration make the femtosecond lasers suitable for applications such as material processing, supercontinuum generation, mid-infrared spectroscopy, micromachining, and imaging. 

Pulsed lasers

The femtosecond fiber lasers usually emit laser pulses with a duration of 50 to 500 fs and have a repetition rate from 10 to 100 MHz. The femtosecond dye lasers offer a pulse duration of up to a hundred femtoseconds.

Specifications of femtosecond lasers

Wavelength: Represents the wavelength of laser light emitted from a femtosecond laser. These lasers are available in UV range to the IR range. The wavelength is represented in a nanometer (nm).

Tunable: Represents the wavelength tune-ability of the femtosecond laser. Both the tuneable and non-tuneable femtosecond lasers are available.

Fiber-coupled: The femtosecond lasers are available both in fiber couple or non-fiber coupled choices.

Operation mode: Pulsed Lasers

Laser color: Represents the laser colour. The femtosecond lasers are available from UV to the IR spectrum.

Mode: Represents the mode of operation of laser light. Usually, these lasers are available in single-mode.

Power: Represents the power average power of a femtosecond laser output. It can have a range of milliwatts to watt range.

Pulse width: Represents the pulse duration of a femtosecond laser. The duration of pulse range is in the femtosecond (10^-15 s) range.

Pulse energy: Represents the energy per pulse of a femtosecond laser. Usually, it is in the range from nJ to mJ range.

Polarization: Represents the polarization mode of light. The femtosecond lasers can be horizontal/vertical polarized.

Repetition rate: Represents the number of emitted pulses per second from a femtosecond laser. It is represented in Hz. For example, the repetition rate of 200 Hz means that 200 pulses per second emitted from the pulse laser. Usually, the repetition rates can from kHz to GHz.    

Beam divergence: Represents the divergence of the laser. Usually, it is represented in milliradian (mrad).