Low-loss waveguides fabricated in BK7 glass by high repetition rate femtosecond fiber laser.
For the first time femtosecond-laser writing has inscribed low-loss optical waveguides in Schott BK7 glass, a commercially important type of borosilicate widely used in optical applications. The use of a variable repetition rate laser enabled the identification of a narrow processing window at 1 MHz repetition rate with optimal waveguides exhibiting propagation losses of 0.3 dB/cm and efficient mode matching to standard optical fibers at a 1550 nm wavelength. The waveguides were characterized by complementary phase contrast and optical transmission microscopy, identifying a micrometer-sized guiding region within a larger complex structure of both positive and negative refractive index variations.
Eaton
Shane M
SM
Department of Electrical and Computer Engineering and Institute for Optical Sciences, University of Toronto, Toronto, Ontario, Canada. shane.eaton@utoronto.ca
Ng
Mi Li
ML
Bonse
Jörn
J
Mermillod-Blondin
Alexandre
A
Zhang
Haibin
H
Rosenfeld
Arkadi
A
Herman
Peter R
PR