Diamond drumhead crystals for X-ray optics applications

Abstract

Thin (<50 mm) and flawless diamond single crystals are essential for the realization of numerous advanced X-ray optical devices at synchrotron radiation and free-electron laser facilities. The fabrication and handling of such ultra-thin components without introducing crystal damage and strain is a challenge. Drumhead crystals, monolithic crystal structures composed of a thin membrane furnished with a surrounding solid collar, are a solution ensuring mechanically stable strain-free mounting of the membranes with efficient thermal transport. Diamond, being one of the hardest and most chemically inert materials, poses significant difficulties in fabrication. Reported here is the successful manufacture of diamond drumhead crystals in the [100] orientation using picosecond laser milling. Subsequent high-temperature treatment appears to be crucial for the membranes to become defect free and unstrained, as revealed by X-ray topography on examples of drumhead crystals with a 26 mm thick (1 mm in diameter) and a 47 mm thick (1.5 Â 2.5 mm) membrane.

Small Bragg-plane slope errors revealed in synthetic diamond crystals

“…Is it possible to eliminate the strain induced by laser cutting? In our previous studies (Kolodziej et al, 2016) we found that annealing diamond crystals in air at a temperature of 630-650 C for 3 h may substantially reduce strain induced in the process of laser cutting or ablation. The strain is caused by the graphitization of the machined surfaces.…”

An x-ray regenerative amplifier free-electron laser using diamond pinhole mirrors

“…The utility of an x-ray FEL oscillator (XFELO) has been under study for a decade [7][8][9][10][11][12][13][14] making use of resonators based upon Bragg scattering from high-reflectivity diamond crystals [15][16][17][18][19]. The development of these crystals is a major breakthrough in the path toward an XFELO.…”

Population inversion X-ray laser oscillator

“…Outcoupling was done by switching to a status with large transmission and near-zero reflection. Several techniques for radiation outcoupling, including a small fast rotation or heating with a laser pulse, can be employed and are currently being studied (57)(58)(59). We chose the backscattering Bragg geometry, as it provides a large angular acceptance while reducing the bandwidth (Table 1 and Fig.…”