We have been developing a compact and lightweight X-ray micropore optics for small satellite mounting. We achieved three-dimensional machining into a single flat glass substrate by femtosecond laser irradiation and wet etching. In addition to the three-dimensional machining, we applied annealing and magnetic fluid polishing to reduce surface roughness of inner walls, and coated the surface with Pt layer by ALD to improve the reflectance. In this paper, we introduce our achievement on micromachining into a single flat glass substrate. As principle verification, we achieved extremely small hole with 2μm diameter and 100μm depth, slit with 10μm width, 2500(50×50) multiple through holes in 26μm pitch and hole angle control within 0.15 degree. We will further develop manufacturing techniques and explore other applications of our micropore optics, such as fundamental research, security inspection and infrastructure inspection.
Compact and lightweight X-ray micropore optics with high quality stability have been developed utilizing our microfabrication technology. We have fabricated Schmidt type Lobster Eye Optics named Pre Bread Board Model (PreBBM). This optics has a plurality of oblique grooves having a width of 10 um formed by laser modification and wet etching in flat glass substrate. Both smoothing by annealing and Pt coating were applied on the groove surface to complete Pre-BBM. And we conducted the first X-ray irradiation test. In order to obtain high X-ray reflectivity, next challenge is to reduce surface roughness of the micropore side wall to nanometers or less. We adopted magnetic fluid polishing and glass annealing technology as a method to reduce surface roughness of the glass. We are trying to optimize the condition to achieve side wall surface roughness of 1 nm.