Growth of a multilayer garnet crystal double-clad waveguide structure by pulsed laser deposition

Abstract

We report the growth of a multilayer garnet crystal double-clad waveguide structure by Pulsed Laser Deposition. The structure, grown on a YAG (100) substrate, was fabricated from the sequential deposition of YGG, Nd,Cr:GSGG, YGG and YAG, each layer being about 1 micron in thickness. X-ray diffraction analysis has shown that the layers all grew in the epitaxial (100) orientation and energy dispersive X-ray analysis has revealed that the layer compositions are close to those of the target materials. The success of this trial fabrication is an indication of the capability of PLD to produce designer multilayer planar waveguide structures.

Growth of a hybrid garnet crystal multilayer structure by combinatorial pulsed laser deposition

“…It can be seen that surface roughness introduced by particulates in the initial layers is amplified in subsequent layers. Particulates are a significant drawback for the PLD technique, but it is expected that further spatial optimisation of the laser pulses will lead to a significant reduction in particulate density, and will also improve the layer interface smoothness as a result, as has been observed for previous multilayer deposition experiments performed using a KrF excimer laser [20]. Polishing between layer depositions can also be performed to solve the problem of surface roughness, though continuously graded growth may negate the need for this extra processing step by removing the distinct interface altogether.…”

“…Garnets are usually excellent host materials [17] and can be grown by PLD without adversely affecting their stoichiometry or crystallinity to any significant degree. It has been shown recently that it is possible to fabricate multilayer structures composed of separate single crystalline garnet thin films [20] suitable for fabricating cladding-pumped waveguide lasers [21].…”

New raster-scanned <inline-formula><math display="inline" overflow="scroll"><mrow><msub><mrow><mi>CO</mi></mrow><mrow><mn mathvariant="bold">2</mn></mrow></msub></mrow></math></inline-formula> laser heater for pulsed laser deposition applications: design and modeling for homogenous substrate heating

“…Formation of epitaxial complex oxides such as YAG (Y 3 Al 5 O 12 ) or any other member from the garnet family requires oxygen ambient and high temperatures around 1000 to 1100 K. [1][2][3][4] Garnets are excellent laser hosts that have been grown in both single film and multilayer geometries. Formation of epitaxial complex oxides such as YAG (Y 3 Al 5 O 12 ) or any other member from the garnet family requires oxygen ambient and high temperatures around 1000 to 1100 K. [1][2][3][4] Garnets are excellent laser hosts that have been grown in both single film and multilayer geometries.…”

“…The enthusiastic reader is referred to May-Smith et al 4 for a comprehensive historical review of the beam homogenization techniques. 2 Hence, any raster scanning heating system must expose the outer regions of the substrate for a longer period of time, which counter-balances the effect of the radiation losses at the edges. The newly reported ZnSe tetraprism optic 4 is actually designed for square-shaped substrates and not applicable for disk-shaped ones.…”

Comparative growth study of garnet crystal films fabricated by pulsed laser deposition

“…However, previous reports of laser operation in Nd:Gd 3 Ga 5 O 12 (GGG) [9] PLD grown planar laser waveguides with a low loss of 0.1 dB cm À1 [10] show that their effect can also be minimised by using simple experimental procedures such as reconditioning target surfaces and performing thick film depositions in multiple runs. More recently, the trial growth of a multilayer double-clad planar waveguide structure consisting of a core of Nd,Cr:Gd 3 Sc 2 Ga 3 O 12 (GSGG); inner cladding layers of Y 3 Ga 5 O 12 (YGG) and outer cladding layers of YAG has been reported [11], proving that epitaxial multilayer growth of different garnet compositions is possible.…”