<title>Design and fabrication of fiber Bragg gratings for vertical cavity surface emitting laser diodes</title>

Abstract

We simulated chirped and apodized fiber Bragg gratings (fiber gratings with modulation of the amplitude and with modulation of the spacing) the same as uniform fiber gratings. Results of our simulations are presented. Apodization of fiber Bragg gratings (FBG) has many advantages in comparison to other types of FBGs. Main improvement is suppressing of the side lobes in the grating spectral properties. The difference of side lobes suppression for uniform and Gaussian apodized grating is more than 110dB. On the basis of these results we designed a special fiber Bragg grating with apodization especially for using to stabilize semiconductor lasers for high precision laser applications with central wavelength 760nm. We present application of methods for calculation of parameters of apodized fiber Bragg gratings (FBG). We used combination of methods based on layered dielectric media (LDM) and the transfer matrix. On the contrary to the other calculation techniques the LDM method is based on sequence of thin films of dielectric media assembled in the direction of wave propagation. The combination of the LDM method and the transfer matrix method can be used to the calculation of arbitrary fiber gratings with high precision. For this designed apodized FBG we calculated the phase mask to manufacture by interference patterns. The phase mask and the fixation bottom of the fiber were made by e-beam lithography to achieve highly precise stability during manufacturing. We present the set-up of this system for writing FBG by pulsed UV laser with wavelength 266nm. Measurement of commercially available FBG with comparison to our calculated FBG is presented.