Microstructuring of Nd:YAG crystals by proton-beam writing

Abstract

We report on the microstructuring of Nd:YAG crystals by direct proton-beam writing. Buried channel waveguides have been fabricated with full spatial control by the combined variation of crystal position and proton energy. The fluorescence images of the obtained structures have been used to evaluate the potential application of the fabricated structures for laser gain as well as to elucidate the mechanism at the basis of the refractive index increment induced at the end of the proton path. We have concluded that this increment is very likely a local enhancement in the electronic polarizability caused by nuclear collisions.

Continuous wave Nd:YAG channel waveguide laser produced by focused proton beam writing

“…The proton beam was at energy of 1 MeV and focused down to a beam with diameter of 1μm. During the process, the sample was mounted on a motorized stage (Exfo inchworm stage, moving linearly at different speeds), and the proton beam was magnetically scanned over a distance of 4μm in a perpendicular direction to the proton pathway on the x-y face, reaching different writing fluences of 1×10 15 , 5×10 15 , 1×10 16 , and 2×10 16 cm 2 . The formed channel waveguides were along the 4.8-mm axis of the wafer.…”

“…As of yet, successful examples of PBW waveguides include a few organics materials (e.g., PMMA, SU-8) glasses and crystals [13][14][15][16][17].…”

“…Waveguide lasers have been already fabricated in this material (in both single crystals and polycrystalline ceramics) by using a few techniques, such as ion implantation, femtosecond laser inscription, femtosecond laser ablation, film deposition, and waveguide lasers have been generated in some of these samples [18][19][20][21][22][23]. Despite the fact that PBW has been recently demonstrated to be a powerful technique for the fabrication of high quality channel waveguides in Nd:YAG with 3D control [16], the suitability of the obtained waveguides as integrated laser gain medium has not, to the best of our knowledge, been reported up to now. In this work, we report on the first demonstration of continuous wave stable laser operation at 1064 nm at room temperature from a 808 nm pumped Nd:YAG channel waveguide fabricated by PBW.…”

Superficial waveguide splitters fabricated by femtosecond laser writing of LiTaO 3 crystal

“…12,13 It possesses better thermal stability for high-power laser processing and prominent ability for photorefraction, especially for an MgO-doped crystal, compared with the commonly used LiNbO 3 . [23][24][25] High-intensity femtosecond laser pulses allow the micromodification of the material matrix with an extreme precision through strong-field ionization processes. [18][19][20][21][22] Direct femtosecond laser writing has recently become a powerful technique to realize three-dimensional (3-D) micromachining of diverse materials for a broad range of applications.…”

Proton Beam Writing of Chalcogenide Glass: A New Approach for Fabrication of Channel Waveguides at Telecommunication O and C Bands

“…Some controlled micro-modifications occur in the scanning area. Concerning the optical properties, in most of the glasses [30], [33], [34] and some crystals (e.g., Nd:YAG and Nd:GGG) [27], [28], the proton or He + induces an increase of the refractive index in the scanning volume, typically located at the end of the ion track. This feature enables construction of buried waveguides instead of surface ones in some optical materials.…”