Abstract: A semiconductor laser diode (LD) with a shortened cavity length is disclosed. The LD provides a rectangular substrate and, on the substrate, a cavity structure including a mesa with facets forming the laser cavity. The facets of the mesa are stood back from the side of the substrate. Pads to provide electrical signals are arranged in both sides of the mesa close to the sides of the substrate.

Abstract: A transmitter module that includes a laser diode (LD) and a driver, each mounted on a sub-mount, is disclosed. The driver directly drives the LD by supplying a modulation signal, a bias signal, and a reference. Two signals are provided to a first pad of the LD, while, the reference is provided to the second pad of the LD. The second pad in the center thereof is formed relatively closer to the second facet of the LD opposite to the first facet through which the laser light is emitted.

Abstract: A semiconductor laser diode (LD) with a shortened cavity length is disclosed. The LD provides a rectangular substrate and, on the substrate, a cavity structure including a mesa with facets forming the laser cavity. The facets of the mesa are stood back from the side of the substrate. Pads to provide electrical signals are arranged in both sides of the mesa close to the sides of the substrate.

Abstract: A transmitter module that includes a laser diode (LD) and a driver, each mounted on a sub-mount, is disclosed. The driver directly drives the LD by supplying a modulation signal, a bias signal, and a reference. Two signals are provided to a first pad of the LD, while, the reference is provided to the second pad of the LD. The second pad in the center thereof is formed relatively closer to the second facet of the LD opposite to the first facet through which the laser light is emitted.

Abstract: An optical multilayer film includes: a first layer; a second layer that contains titanium oxynitride as a main component; and a third layer that contains magnesium fluoride as a main component; the first layer that has a different refractive index from that of the second layer or the third layer; and the first layer, the second layer, and the third layer being part of a laminated structure that includes a plurality of reflection planes. The thickness of the third layer is smaller than ¼ wavelength.

Abstract: An electrode structure includes a conductive film 24c formed on a base substrate 10 through an insulation film. The insulation film comprises a plurality of poles 36 of polyimide, a first film 38 formed on the side surfaces of the poles and formed of an insulation material of a high hardness than polyimide, and a second film 40 of polyimide buried among the plural poles with the first film formed on the side surfaces thereof. Because of the first film of an insulation material having high hardness formed on the side surfaces of the poles of polyimide, even when a strong force is applied upon the bonding, the poles are prevented from being distorted, and the conductive film is protected from peeling off. Because of the thick polyimide layer below the conductive film, a parasitic capacity between the conductive film and the lower layer can be small, whereby radio-frequency signals can be used.

Abstract: An optical multilayer film includes: a first layer; a second layer that contains titanium oxynitride as a main component; and a third layer that contains magnesium fluoride as a main component; the first layer that has a different refractive index from that of the second layer or the third layer; and the first layer, the second layer, and the third layer being part of a laminated structure that includes a plurality of reflection planes. The thickness of the third layer is smaller than ¼ wavelength.

Abstract: An optical film of the present invention is of multi-layered structure which has a high-refractive-index layer composed of titanium oxidic nitride, aluminum oxidic nitride, or silicon oxidic nitride.