METHOD AND ARRANGEMENT IN CONNECTION WITH OPTICAL BRAGG-REFLECTORS

摘要

A method of establishing transmission of light through a chirped Bragg-reflector, a method of analysing the power spectrum of a light signal by means of a chirped Bragg-reflector, and an arrangement for analysing the power spectrum of a light signal. The Bragg-reflector reflects, in an unperturbed state, essentially all incident light within a predefined wavelength range. The methods comprise the steps of directing the light to be analysed into an input end of a light guiding structure, such as an optical fibre, which light guiding structure is provided with a Bragg-reflector, and sending an acoustic pulse along said light guiding structure, thereby effectively lowering the reflectance of the Bragg-reflector for a certain wavelength at a certain time. By monitoring the light thus transmitted through the Bragg-reflector, power spectrum analysis of the incident light is obtained.