One of the greatest problems that the world is facing today is that of environmental pollution, increasing with every passing year and causing grave and irreparable damage to the earth. Environmental pollution consists of five basic types of pollution, namely, air, water, soil, noise and light. Air pollution is by far the most harmful form of pollution in our environment. Air pollution is caused by the injurious smoke emitted by cars, buses, trucks, trains, and factories, namely sulphur dioxide, carbon monoxide and nitrogen oxides. The real-time detection of trace pollutants in the atmosphere is of great interest to a wide range of fields, including environmental science, safety monitoring, air quality control, defense and homeland security, and medical diagnostics. Atmospheric pollutant monitors use different technologies as: electrospray mass spectrometry, adaptive infrared imaging spectro-radiometry, millimeter wave technology, chemical agent monitoring, and electro kinetic injection in capillary electrophoresis, surface acoustic wave chemical sensors. Each, however, has drawbacks and limitations. In general, these are delicate, stationary, and expensive equipment demanding complex and time-consuming sample preparation. Laser-based techniques for trace detection of environment pollution have many advantages over other techniques because of their ability to provide real-time monitoring capabilities with greater sensitivity and selectivity. In this project we propose for the first time, a novel device for the fast and accurate monitoring of environmental pollution, based on the multiline two-dimensional cascade cholesteric liquid crystal laser. One of the most promising materials in the field of soft-matter photonics, that may be the key elements for the development a new era of compact multicolor laser sources, are the cholesteric liquid crystals. From a practical point of view, as opposite to semiconductor and solid state lasers, using cholesteric liquid crystal lasers any wavelength can be obtained, from ultraviolet to near infrared, simply by adjusting the position of the photonic band gap and properly selecting the luminescent dopant for the desired wavelength range. As a result, multi laser lines, in the visible and near infrared ranges of the optical spectrum, can be simultaneously emitted under a one UV pumping laser source. Using a diffractive element, it is possible to provide a two-dimensional distribution of the laser lines for practical applications. The proposed idea will provide a new concept for the potential solutions in the development of compact laser light sources able to simultaneously produce a broad multiline light emission. At the end of the project implementation we aim to demonstrate a laboratory based device that can be used to fabricate robust and reliable detectors for the in situ rapid and accurate determination of major atmospheric pollutant contamination, where the accuracy, cost-efficiency, rapidity and portability play an important role as in global and homeland security, medicine and food industry.
