Enhanced Second Harmonic Generation in Femtosecond Laser Inscribed Double-Cladding Waveguide of Nd:GdCOB Crystal

Author

Yuechen Jia ; Vazquez de Aldana, Javier Rodriguez ; Qingming Lu ; Jaque, D. ; Feng Chen

Author_Institution

State Key Lab. of Crystal Mater., Shandong Univ., Jinan, China

Volume

31

Issue

23

fYear

2013

fDate

Dec.1, 2013

Firstpage

3873

Lastpage

3878

Abstract

We report on the fabrication of double-cladding waveguides in Nd:GdCOB crystals by using femtosecond laser inscription with scanning speed of 0.5 mm/s. This prototype consists of two concentric tubular structures with nearly circular cross sections with different diameters. The fabricated cladding waveguides possess relatively low propagation losses of less than 0.65 dB/cm. The micro photoluminescence and second harmonic confocal images of the fabricated waveguides, which were performed by using a confocal microscope, have revealed that neither the fluorescence nor the nonlinear properties of the constituent crystals have been deteriorated during femtosecond laser micromachining procedure. Under the pulsed laser pumping at fundamental wavelength of 1064 nm, the guided wave second harmonic generation (SHG) at 532 nm has been realized from the single and double cladding waveguides. Compared to the single-claddings (2.3 or 4.7%, depending on the diverse cladding diameters), the double cladding architecture has been found to be with enhanced SHG conversion efficiency (~5.1%).

Keywords

claddings; fluorescence; gadolinium compounds; high-speed optical techniques; laser beam machining; laser materials processing; light propagation; micromachining; neodymium; optical fabrication; optical harmonic generation; optical losses; optical microscopes; optical pumping; optical waveguides; photoluminescence; prototypes; GdCOB:Nd; SHG conversion efficiency; circular cross sections; cladding diameters; concentric tubular structures; confocal microscope; femtosecond laser inscribed double-cladding waveguide; femtosecond laser micromachining; fluorescence; fundamental wavelength; guided wave second harmonic generation; low propagation losses; microphotoluminescence; nonlinear properties; prototype; pulsed laser pumping; scanning speed; second harmonic confocal images; wavelength 1064 nm; wavelength 532 nm; Crystals; Laser excitation; Optical device fabrication; Optical waveguides; Pump lasers; Ultrafast optics; Waveguide lasers; Femtosecond laser inscription; Nd:GdCOB crystal; optical waveguides; second harmonic generation (SHG);

fLanguage

English

Journal_Title

Lightwave Technology, Journal of

Publisher

ieee

ISSN

0733-8724

Type

jour

DOI

10.1109/JLT.2013.2288371

Filename

6654283