Narrowband chirped thin film filters with distributed cavity

In this paper we report on narrowband optical filters with chirped thin films. The continuous variation of the layer thickness represents the cavity of a Fabry-Pérot resonator that has been distributed over the device. New design parameters are accessible for tailoring filter properties and the option to obtain a more even distribution of resonant modes may improve the performance of VCSEL devices. Results of the numerical investigation of these chirped filters as well as our experimental results of their fabrication and characterization are presented and discussed.