High-precision optomechanical lens system for space applications assembled by a local soldering technique

Abstract

Soldering using metallic solder alloys is an alternative to adhesive bonding. Laser-based soldering processes are especially well suited for the joining of optical components made of fragile and brittle materials such as glass, ceramics, and optical crystals. This is due to a localized and minimized input of thermal energy. Solderjet bumping technology has been used to assemble a lens mount breadboard using specifications and requirements found for the optical beam expander for the European Space Agency EarthCare Mission. The silica lens and a titanium barrel have been designed and assembled with this technology in order to withstand the stringent mission demands of handling high mechanical and thermal loads without losing the optical performance. Finally, a high-precision optomechanical lens mount has been assembled with minimal localized stress (<1 MPa) showing outstanding performance in terms of wave-front error and beam depolarization ratio before and after environmental tests

A review on glass welding by ultra-short laser pulses

“…As an example, while mechanical mounting [6], gluing [7] and soldering [8] are fairly straightforward glass joining techniques, they are not optimal when additional (and thus different) materials are present in the joint, which causes a mismatch of thermal expansion coefficients and reduced chemical stability. This deficiency is not present when no additives are used.…”

Laser Technology in Photonic Applications for Space

“…Packaging issues can be solved by using new packaging technologies. Replacing adhesives by techniques, such as low-stress soldering techniques [141], will contribute towards providing more robust DPSSL devices with higher thermal range, higher mechanical strength, lower out-gassing, and improved bonded-materials resistant to radiation.…”

Effect of physical parameters of laser radiation on the process of weld formation in transparent dielectrics

“…Today, the main methods of glass connection are mechanical installation [4], gluing and fusion [5]. These methods, although easy to use, are not optimal, since they include additional materials other than glass, which can reduce the chemical stability and mechanical strength of the compound [4].…”