Nanoindentation studies on waveguides inscribed in chalcogenide glasses using ultrafast laser

Optical straight waveguides are inscribed in GeGaS and GeGaSSb glasses using a high repetition-rate sub-picosecond laser. The mechanical properties of the glasses in the inscribed regions, which have undergone photo induced changes, have been evaluated by using the nanoindentation technique. Results show that the hardness and elastic modulus of the photo-modified glasses are significantly lower as compared to the other locations in the waveguide, which tend to be similar to those of the unexposed areas. The observed mechanical effects are found to correlate well with the optical properties of the waveguides. Further, based on the results, the minimum threshold values of hardness and elastic modulus for the particular propagation mode of the waveguide (single or multi), has been established. ©2013 Optical Society of America OCIS codes: (230.3120) Integrated optics devices; (140.3390) Laser materials processing; (320.7130) Ultrafast processes in condensed matter, including semiconductors. References and links 1. A. Zakery and S. R. Elliott, “Optical properties and applications of chalcogenide glasses: a review,” J. NonCryst. Solids 330(1-3), 1–12 (2003). 2. B. J. Eggleton, B. L. Davis, and K. Richardson, “Chalcogenide photonics,” Nat. Photonics 5, 141–148 (2011). 3. D. Lezal, J. Pedlikova, and J. Zavadil, “Chalcogenide glasses for optical and photonics applications,” J. Optoelectron. Adv. Mater. 6, 133–137 (2004). 4. A. B. Seddon, “Chalcogenide glasses: a review of their preparation, properties and applications,” J. Non-Cryst. Solids 184, 44–50 (1995). 5. J. S. Sanghera and I. D. Aggarwal, “Active and passive chalcogenide glass optical fibers for IR applications: a review,” J. Non-Cryst. Solids 256-257, 6–16 (1999). 6. J. A. Frantz, L. B. Shaw, J. S. Sanghera, and I. D. Aggarwal, “Waveguide amplifiers in sputtered films of Erdoped gallium lanthanum sulfide glass,” Opt. Express 14(5), 1797–1803 (2006). 7. S. J. Beecher, R. R. Thomson, N. D. Psaila, Z. Sun, T. Hasan, A. G. Rozhin, A. C. Ferrari, and A. K. Kar, “320 fs pulse generation from an ultrafast laser inscribed waveguide laser mode-locked by a nanotube saturable absorber,” Appl. Phys. Lett. 97(11), 111114 (2010). 8. S. R. Ovshinsky, “Reversible electrical switching phenomena in disordered structures,” Phys. Rev. Lett. 21(20), 1450–1453 (1968). 9. K. M. Davis, K. Miura, N. Sugimoto, and K. Hirao, “Writing waveguides in glass with a femtosecond laser,” Opt. Lett. 21(21), 1729–1731 (1996). 10. A. Ródenas, G. Martin, B. Arezki, N. Psaila, G. Jose, A. Jha, L. Labadie, P. Kern, A. K. Kar, and R. R. Thomson, “Three-dimensional mid-infrared photonic circuits in chalcogenide glass,” Opt. Lett. 37(3), 392–394 (2012). 11. L. B. Fletcher, J. J. Witcher, N. Troy, S. T. Reis, R. K. Brow, R. M. Vazquez, R. Osellame, and D. M. Krol, “Femtosecond laser writing of waveguides in zinc phosphate glasses [Invited],” Opt. Mater. Express 1(5), 845– 855 (2011). 12. T. Sabapathy, A. Ayiriveetil, A. K. Kar, S. Asokan, and S. J. Beecher, “Direct ultrafast laser written C-band waveguide amplifier in Er-doped chalcogenide glass,” Opt. Mater. Express 2(11), 1556–1561 (2012). 13. R. R. Gattass and E. Mazur, “Femtosecond laser micromachining in transparent materials,” Nat. Photonics 2(4),