What are Tunable Lasers?

Tunable laser are lasers whose wavelength can be adjusted (tuned) in a controlled manner. These lasers operate from wavelengths in the UV range to the IR region. They are available in both CW and Pulsed operating modes. Tunable lasers are ideal for ultrafast Imaging, photochemistry, harmonic generation, medical, scientific, nano-surgery, pump-probe, and spectroscopy applications.

Some of the examples of tunable lasers are excimer lasers, gas lasers (such as CO2 and He-Ne lasers), dye lasers (liquid and solid-state), transition metal solid-state lasers, semiconductor crystal, and diode lasers, and free-electron lasers.

Tunable lasers usually use components such as a Lyot filter in the optical cavity, which can help tune the wavelength. Other methods of tuning the wavelength include diffraction gratings, prisms, etalons, and combinations of these, and multiple-prism grating arrangements.

Tunable Dye Laser

Specifications of Tunable Lasers

Wavelength: Represents the tuning ability range. Based on the technology and active medium, the range of wavelength can be varied from UV to IR range. The wavelength is represented in a nanometer (nm).

Fiber-coupled: The tuneable lasers are available both in fiber-coupled or non-fiber coupled options.

Operation mode: Represents the operation mode. These lasers are available both in continuous wave (CW) and pulsed mode operation. 

Laser color: Represents the laser color of the tuneable lasers. Usually, it varies from UV to IR range. 

Mode: Represents the mode of operation of laser light. It can be single-mode or multi-mode.

Power: Represents the power output of the tuneable lasers. It can have the range of milliwatts up to kilo watts range.

Pulse width: Represents the pulse duration of the tuneable laser working in pulsed mode of operation.

Pulse energy: Represents the energy per pulse of the tuneable laser working in pulsed mode of operation. Usually, it is in range from pJ to J (joule) range. This can be adjusted in tunable lasers.

Repetition rate: Represents the number of emitted pulses per second from the tuneable pulsed laser .It is represented in Hz. For example, the repetition rate 10 Hz means that 10 pulses per second emitted from the pulse laser. Usually, the repetition rate of the tuneable laser can vary from Hz to MHz range. 

Beam diameter: Represents the beam diameter of the tuneable laser in mm .

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