title: Integrated-optical wavelength sensor with self-compensation of thermally induced phase shifts by use of a LiNbO3 unbalanced Mach-Zehnder interferometer.
abstract: We demonstrate an integrated-optical unbalanced Mach-Zehnder interferometer in lithium niobate for detecting wavelength shifts of light sources, such as laser diodes and superluminescentdiodes at lambda = 844 nm. The output signal can be used to stabilize the light source. Because of the temperature dependence of the effective refractive index and the thermal expansion of the substrate, the device acts also as a temperature sensor. The temperature sensitivity of the interferometer was compensated for by the combination of proton exchanged- and annealed proton exchanged-channel waveguides by approximately two orders of magnitude. The thermo-optic coefficients of the extraordinary effective refractive index in integrated optical channel waveguides in LiNbO8 have been measured with high accuracy over a temperature range from 10 degrees C to 40 degrees C.
authors.affiliation: Institute of Applied Physics, Friedrich-Schiller-University Jena, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Grusemann
authors.forename: Brit
authors.initials: B
authors.lastname: Zeitner
authors.forename: Matthias
authors.initials: M
authors.lastname: Rottschalk
authors.forename: Jens-Peter
authors.initials: JP
authors.lastname: Ruske
authors.forename: Andreas
authors.initials: A
authors.lastname: Tünnermann
authors.forename: Andreas
authors.initials: A
authors.lastname: Rasch