Femtosecond-laser-written superficial cladding waveguides in Nd:CaF2 crystal. (1st July 2017)

• Record Type: Journal Article
• Authors: Li, Rang; Nie, Weijie; Lu, Qingming; Cheng, Chen; Shang, Zhen; Vázquez de Aldana, Javier R.; Chen, Feng
• Is Part Of: Optics & laser technology. Volume 92(2017)
• Page Start: 163
• Page End: 167
• Publication Date: 2017-07-01
• Subjects: Optical waveguides -- Nd:CaF2 crystal -- Femtosecond laser writing; Optics -- Periodicals; Lasers -- Periodicals; Electronic journals; 621.366
• DOI: 10.1016/j.optlastec.2017.01.026
• Languages: English
• ISSNs: 0030-3992

Abstract

Abstract: We report on the superficial cladding waveguides fabricated by direct femtosecond laser writing in Nd: CaF2 crystal with three different groups of parameters. The lowest propagation loss of waveguides has been determined to be 0.7 dB/cm at wavelength of 632.8 nm along TE polarization. The near fundamental modal distributions have been imaged through the end-face coupling technique. The guidance of the waveguides is found to possess low sensitivity on polarization of the probe light. By using a confocal microscope system, the micro-photoluminescence mappings and micro-fluorescence spectra are also obtained, which indicates the photoluminescence features of the Nd 3+ ions are well preserved in the waveguide cores after direct femtosecond laser writing. Highlights: Superficial waveguides were fabricated in Nd: CaF2 by femtosecond laser writing. The near fundamental modal distributions and low propagation loss. The low sensitivity on polarization and well-preserved photoluminescence.