Abstract: An improved method for forming inexpensive, lightweight, closed-back, silicon carbide mirrors, via chemical vapor deposition (CVD) or chemical vapor composites (CVC), is achieved by using a two dimensional corrugated core with sloped walls. All layers in this design are chemical vapor deposited optical grade silicon carbide. Seamless cohesion between layers is achieved by depositing the material on the sloped walls of, and through holes in, the mandrel. The resulting structure is cohered and monolithic. The mandrels are matched in coefficient of thermal expansion (CTE) to the deposited material. Mandrels that support the layers are later removed by a separate process.

Abstract: An improved method for forming inexpensive, lightweight, closed-back, silicon carbide mirrors, via chemical vapor deposition (CVD) or chemical vapor composites (CVC), is achieved by using a two dimensional corrugated core with sloped walls. All layers in this design are chemical vapor deposited optical grade silicon carbide. Seamless cohesion between layers is achieved by depositing the material on the sloped walls of, and through holes in, the mandrel. The resulting structure is cohered and monolithic. The mandrels are matched in coefficient of thermal expansion (CTE) to the deposited material. Mandrels that support the layers are later removed by a separate process.

Abstract: A light-weight mirror blank assembly, having at least one sheet of corrugated material; and at least one face sheet in intimate contact with a surface of the sheet of corrugated material forming the light-weight mirror blank assembly. The light-weight mirror blank assembly has an areal density less than an equivalent blank assembly having a solid support structure for supporting a mirrored surface.

Abstract: An apparatus, system and method for grinding or polishing an optic is provided. The apparatus includes a shell adapted to a bending profile, torque actuators attached at an outer edge of the shell and coupled to each other, a tensioning system attached at the outer edge of the shell, and a control system for computing the bending profile and controlling the torque actuators and tensioning system. The torque actuators and tensioning system apply bending moments to the edge of the shell to adapt the shell according to the bending profile provided by the control system. A calibration system further corrects errors in a measured bending profile.

Abstract: A device and method for measuring a fusion seal quality within a structure comprising a source for providing a focused optical beam of a known intensity to a fusion seal within a structure, the fusion seal reflecting the optical beam according to the fusion seal quality, a receiver for receiving the reflected optical beam and a processor are presented for measuring a intensity ratio between the reflected optical beam and the focused optical beam relating to fusion seal quality. The device may scan the structure and provide an intensity ratio image map for a region within the structure related to fusion seal quality.

Abstract: A method for constructing a mirror blank, including arranging hollow glass balls, on a front face sheet, and in close proximity to each other to permit fusing upon expansion; restricting the expansion of the hollow glass balls with a bounding structure during expansion of the hollow glass balls to force the hollow glass balls into a densely packed array of cells; applying heat to soften the hollow glass balls and increase the pressure within the hollow glass balls as the hollow glass balls fuse with each other during expansion, forming cells, wherein as a result of fusing, the hollow glass balls contact the front face sheet as a result of the increased pressure within the hollow glass balls; annealing and cooling the mirror blank to below annealing temperature associated with the hollow glass balls; and venting the cells.

Abstract: A method for constructing a mirror blank, including arranging hollow glass balls, on a front face sheet, and in close proximity to each other to permit fusing upon expansion; restricting the expansion of the hollow glass balls with a bounding structure during expansion of the hollow glass balls to force the hollow glass balls into a densely packed array of cells; applying heat to soften the hollow glass balls and increase the pressure within the hollow glass balls as the hollow glass balls fuse with each other during expansion, forming cells, wherein as a result of fusing, the hollow glass balls contact the front face sheet as a result of the increased pressure within the hollow glass balls; annealing and cooling the mirror blank to below annealing temperature associated with the hollow glass balls; and venting the cells.