A tunable laser is a laser whose wavelength of operation can be altered in a controlled manner. While all laser gain media allow small shifts in output wavelength, only a few types of lasers allow continuous tuning over a significant wavelength range.

Tunable diode laser analyzers (TDL analyzers) are gas analyzers designed for measuring the concentration of specific species within a gas mixture using laser absorption spectrometry.

A tunable diode laser emits a wavelength of near-infrared (NIR) light specific for the target analyte into the sample cell where it passes through the gas and is reflected back by a mirror at the opposite end of the cell to a solid state detector.

A relatively new technique using a Tunable Diode Laser (TDL) system to monitor water vapour, carbon dioxide and hydrogen sulphide is providing higher on-line accuracy, lower maintenance, than traditional techniques and is significantly better at coping with contamination.

Tunable Diode Laser (TDL) technology offers a fast-response, accurate measurement that is highly specific to the gas of interest. This causes a reduction of the measured signal intensity, which is detected by a photodiode and used to determine the gas concentration and other properties.

In the simplest form a TDL analyzer consists of a laser that produces infrared light, optical lenses to focus the laser light through the gas to be measured and then on to a detector, the detector, and electronics that control the laser and translate the detector signal into a signal representing the gas concentration.

A tunable laser can be used for device characterization, e.g. of photonic integrated circuits. In optical fiber communications with wavelength division multiplexing, a tunable laser can serve as a spare in the case that one of the fixed-wavelength lasers for the particular channels fails.

The most useful feature of dye lasers is their tunability. The tunability means that the lasing wavelength for a dye may be varied over a wide range. Due to this reason, dye lasers are also called tunable lasers. Tuning over 500 angstrom has been obtained.

Among the types 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.

Pulsed lasers are lasers which emit light not in a continuous mode, but rather in the form of optical pulses (light flashes). Depending on the pulse duration, pulse energy, pulse repetition rate and wavelength required, very different methods for pulse generation and very different types of pulsed lasers are used.

The Laser diode operates in lower power as compared to other laser.

A tunable laser is a type of laser diode that can be adjusted to produce a variable wavelength or frequency. This adjustable function allows the laser to be used for more than one purpose and allows the operator more control over the function of the tunable laser than that which is possible with traditional laser units.

Gas Analyzer is an instrument used to measure the concentration of a known gas in given mixture of gases from a process / stream. Gas Analyzer is used to Monitor Process, Enhance Safety, Increase Efficiency, Monitor Emission and Improve Quality.