AGC Inc.(Headquarters: Tokyo; President: Takuya Shimamura), has developed a glass package that is ideal for encapsulating edge-emitting laser diode (LD) chips (Figure 1). Since both sides of this product are polished surfaces, the light emitted from the LD chip can be efficiently extracted without additional parts such as a prism mirror. In addition, by adding proprietary hermetically solder developed by AGC, simplifies customers' manufacturing process and contributes to extending the life of their laser products. This glass package is currently in the prototyping phase and AGC is aiming for mass production.

Most of current LD chips are "edge emitting type" that emit light to the lateral direction from the edge face. Besides, most of the package has a window only on the top face. As a result a separate prism mirror is necessary to extract light from the LD chip upward, making it difficult to reduce costs and minimize the package size ((1) in Figure 2). Another current solution is bonding the polished window on the side hole of the package. Since bonded with sealing material, it is difficult to attach the window at the precisely right angle so as to project light in the target direction. ((2) in Figure 2)

Furthermore, by adding a special hermetic solder developed by AGC to the frame surface of the aperture, the process of sealing with the ceramic substrate can be completed simply by heating and pressing in the air. This eliminates the need for large-scale deoxidization equipment for the customer. In addition, this special solder is soft enough to reduce the thermal stress generated due to difference of CTE between package and window. This helps to prevent deterioration in airtightness from cracks at the interface after thermal cycle test. As a result, this also contributes to extending the life of the laser package.
AGC has already filed for a patent for this glass package.

Enlarged picture of the newly developed glass package