The writing of an internal diffraction grating in optical glass plate is demonstrated using low-density plasma formation excited by a high-intensity femtosecond Ti:sapphire laser. The same diffraction efficiency at +-1, +-2, and 0 order isachieved by multiple layers writing. The dependences of diffractive efficiency on the irradiated energy, the speed of writing, the numerical aperture (NA) of the focusing objective, and materials are investigated in detail. The grating isbirefringent. It is attributed to residual stress interaction between glass and femtosecond laser pulse.
© 2005 Chinese Optics Letters
(050.1950) Diffraction and gratings : Diffraction gratings
(140.3390) Lasers and laser optics : Laser materials processing
(220.4610) Optical design and fabrication : Optical fabrication
(320.7110) Ultrafast optics : Ultrafast nonlinear optics
Guanghua Cheng, Qing Liu, Yishan Wang, Lianjun Yu, Wei Zhao, and Guofu Chen, "Writing of internal gratings in optical glass with a femtosecond laser," Chin. Opt. Lett. 2, 119-121 (2004)