INTRODUCTION

Tunable lasers are different to traditional lasers because they can continuously change their emission wavelength, or color, in a given spectral range.

As such, these quantum devices have found numerous applications in many diverse fields.

In particular, tunable lasers have played a crucial and sustained role in advancements of fundamental physics and science.

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.

DEFINITION

Tunable lasers as the name suggests are lasers whose wavelengths can be tuned or varied.

They play an important part in optical communication networks

Recent improvements in tunable laser technologies are enabling highly flexible and effective utilization of the massive increases in optical network capacity brought by large-scale application of dense wavelength division multiplexing.

The distributed feedback laser (DFB), the external cavity diode laser, the vertical cavity diode laser and the micro electro mechanical system (MEMS) technology

Tunable lasers are still a relatively young technology, but as the number of wavelengths in networks increases so will their importance.

A tunable laser is a laser whose wavelength of operation can be altered in a controlled manner.

  Tunable lasers are now widely used as light sources in DWDM systems.

  the tunable lasers are used both as a light source in the transmitter and as a local oscillator in the receiver.

  We can use this tunable lasers are enabling highly flexible and effective utilization of the massive increases

in optical network capacity brought by large-scale application of dense wavelength division multiplexing

  Tunable lasers are still a relatively young technology,

ADVANTAGES OF TUNABLE LASER

APPLICATIONS

• 1.spectroscopy

2.photochemistry

3.atomic vapor laser isotope separation,

4. optical communications

5.Spectroscopic Applications of Pulsed Tunable Optical Parametric Oscillators

. 6.Solid-State Dye Lasers

7.Tunable Lasers Based on Dye-Doped Polymer Gain Media Incorporating 8.Homogeneous Distributions of Functional Nanoparticles

CONCLUSIONS

For the 100-Gbit/s system now being developed as a next-generation optical communication system,

we have160 kHz was demonstrated using a TLA with 1500-μm-long DFB lasers

. In addition to the line width characteristics described here, the tunable laser requires higher power, a wider tuning range, and lower power consumption.

Research and development will continue with the aim of obtaining tunable lasers with even better performance

 

REFERENCES

[1] H. Ishii et al., Quasicontinuous wavelength tuning in superstructure- grating (SSG) DBR lasers , IEEE Journal of Quantum

Electronics, Vol. 32, pp. 433-441 (1996)

  [2] G. Morthier et al., A lambda/4-shifted sampled or superstructure grating widely tunable twin-guide

laser, IEEE

Photonics Technol. Lett.Vol. 13, p. 1052-1054,(2001)

 

  [3] J.-O. Wesström et al., Design of a Widely Tunable Modulated Grating Y-branch Laser using the

Additive Vernier Effect for

Improved Super-Mode Selection, accepted to the IEEE International Semiconductor Laser Conference