Integrated Photonic Devices fabricated by direct laser writing

PAULA L. PAGANO; SANTIAGO NOACCO ROSSENDE; SANTIAGO TANCO; DAMIÁN PRESTI; FABIÁN A. VIDELA; GUSTAVO A. TORCHIA

Campinas/ SP

Otro; IONS - ELO (escuela latinoamericana de óptica or, LatinAmerican School of Optics); 2019

OSA-UNIVERSIDADE ESTADUAL DO CAMPINAS (UNICAMP)

In the last years a nontraditional method to fabricate optical circuits in materials has been fruitfully emerged. This technique promises great potential but up to now have not reach the development mature as standard manufacturing technology such as Silicon platform or Titanium diffusion. The method is based on the interaction of ultra-short pulses of laser with optical materials and it was introduced two decades ago from a pioneer paper written by K. Hirao et al. In this paper we presented the study of the optical properties in doped lithium niobate waveguides and middle range ring resonator both devices were fabricated by femtosecond laser writing technique. Waveguides in doped crystals: Waveguides were fabricated in LiNbO3:Tm+3 (LNB) and LiSrAlF6:Cr+3 (LiSAF) both crystals through laser writing. Their propagation modes were studied by coupling polarized light. Meaningly differences between them can be observed only in the LNB waveguides. This seems to indicate that laser writing changes the refractive index anisotropically on that crystal.Additionally, emission spectra of guides and bulk were compared for both crystals. Middle range ring resonator: We designed an optical ring resonator with a radius of 2500 micrometres employing RSoft suite. Using the coherent coupling theory, we determined a suitable geometry based on a regular polygon in order to minimize the bending losses. This structure physically correspond to a guide structure, so a refractive index is a key parameter. The index prole assigned in turn, take values that faithfully represent changes obtained after a femtosecond laser writing process. In order to control the ratio of coupled light into the ring, we have explored and determined the optimal splice angle in closed polygons as a component of ring resonators.