Abstract: A laser diode having a composite passivation layer configured to control parasitic capacitance, especially in high speed laser applications, is disclosed. In one embodiment, a ridge waveguide laser is disclosed and includes: a substrate, an active layer disposed on the substrate, a ridge structure disposed on the active layer, and a contact layer disposed on the ridge structure. A composite passivation layer is disposed substantially laterally to the ridge structure. The composite passivation layer includes a silicon nitride bottom layer, a silicon nitride top layer, and a silicon dioxide middle layer interposed between the bottom and top layers. The passivation layers possess differing stress components that, when combined, cancel out the overall mechanical stress of the passivation layer. This enables relatively thick passivation layers to be employed in high speed laser diodes without increasing the risk of layer stress cracking and laser damage.

Abstract: In one example embodiment, a process for cleaving a wafer cell includes several acts. First a wafer cell is affixed to an adhesive film. Next, the adhesive film is stretched substantially uniformly. Then, the adhesive film is further stretched in a direction that is substantially orthogonal to a predetermined reference direction. Next, the wafer cell is scribed to form a notch that is oriented substantially parallel to the predetermined reference direction. Finally, the wafer cell is cleaved at a location substantially along the notch.

Abstract: In a ridge type semiconductor optical device in which both sides of the mesa stripe are recessed each into a rectangular shape by a depth reaching an active layer, a semiconductor optical device having a structure in which a structure that obstructs conductivity is disposed at a portion on the bottom of a rectangular shape. The structure that obstructs conductivity is attained, for example, by a structure in which impurities are ion implanted into a semiconductor.

Abstract: The subject of the disclosed technique is as follows: a structure in a ridge type semiconductor optical device having both high operation speed and high reliability together is attained.