Abstract: A III-V nitride semiconductor laser device demonstrates an excellent emission characteristic without an increase in production cost. The refractive index of a p-side optical guiding layer is larger than that of an n-side guide layer.

Abstract: A group III nitride semiconductor device producing method is constructed by: a step of forming a first crystal layer made of a group III nitride semiconductor (AlxGa1−x)1−y.InyN (0≦×≦1, 0≦y≦1) doped with a group II impurity element; a step of a second crystal layer made of a group III nitride semiconductor AlzGa1−zN (0.7≦z≦1) onto the first crystal layer; and a step of removing at least a part of the second crystal layer by etching after the formation of the first and second crystal layers.

Abstract: The disclosure is a method for fabricating a nitride semiconductor laser device of group-III nitride semiconductor having a substrate. The method includes a step of forming a crystal layer made of a group-III nitride semiconductor (AlxGa1-x)1-yInyN (0≦x≦1, 0≦y≦1) having an added group II element over the substrate; a step of heating the crystal layer up to a predetermined temperature in a thermal treatment atmosphere and maintaining the predetermined temperature for a first time period; and a step of introducing a hydrocarbon gas into the thermal treatment atmosphere for at least a partial time period within the first time period. The method further includes a step of irradiating an electromagnetic wave or photons to the crystal layer in the at least a partial time period, wherein the electromagnetic wave or photons have an energy greater than an energy forbidden band width of the group III nitride semiconductor in the crystal layer.

Abstract: A GaN type semiconductor layer in which a group 2 impurity element is added is formed. The GaN type semiconductor layer is heated at a predetermined temperature, while irradiating the semiconductor layer with an electromagnetic wave having an energy larger than the band gap energy of the GaN type semiconductor layer.

Abstract: A semiconductor light emitting device has at least a substrate, an n-type GaN type semiconductor layer, an active layer, and a p-type GaN type semiconductor layer which are laminated on each other. In a first annealing process, the semiconductor light emitting device is annealing-processed thereby activating the p-type GaN type semiconductor layer. A metal mask is formed to cover an electric current introducing area of a surface of the p-type GaN type semiconductor layer. In a second annealing process the semiconductor light emitting device is annealing-processed thereby inactivating the p-type GaN type semiconductor layer.

Abstract: A process for producing a semiconductor emitting device of group III nitride semiconductor having a crystal layer (Al.sub.x Ga.sub.1-x).sub.1-y In.sub.y N (0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1) includes; a step of forming at least one pn-junction or pin-junction and a crystal layer (Al.sub.x Ga.sub.1-x).sub.1-y In.sub.y N (0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1) to which a group II element is added; and a step of forming electrodes on the crystal layer. The process further includes an electric-field-assisted annealing treatment in which the pn-junction or pin-junction is heated to the predetermined temperature range while forming and maintaining an electric field across the pn-junction or pin-junction for at least partial time period of the predetermined temperature range via the electrodes.

Abstract: A frequency-changeable microwave signal generator has a plurality of microwave signal oscillators, a plurality of branch lines connected to the microwave signal oscillators, a transmission line connected to the plurality of branch lines and provided with an output port at one end thereof, and a means for selectively operating one of the microwave signal oscillators. The line lengths of the branch lines are set such that the output impedance of the microwave signal oscillator connected thereto, which is measured from a branch point for connecting the transmission line and the branch line, is at maximum when the microwave signal oscillators are inoperative. The relation L=(.lambda./2)(k-1) (k is a natural number) is satisfied where L is a distance along the transmission line between adjacent branch portions of the branch lines connected to the transmission line, and .lambda. is a predetermined operational wavelength.

Abstract: First and second diodes are formed on the same semiconductor substrate. Both the diodes are forward biased by a direct current power supply. An attenuator is connected to a positive terminal of the first diode to produce an output lower in level than a voltage on the positive terminal of the first diode. A comparator receives the output of the attenuator as a first input and a voltage on a positive terminal of said second diode as a second input. When the first input is smaller than the second input, the comparator produces an output "0." When the first diode is open-circuited and the first input becomes greater than the second input, the comparator produces an output "1" and detects the fault of the first diode.

Abstract: A navigation-monitoring apparatus comprises a fixed ground station sending forth an interrogation signal to a ship and a transponder carried on the ship and transmitting a reply signal to the fixed ground station in response to the interrogation signal. A microwave sensor carried on the ship measures the distance between the ship and the nearest bank. Data on the measured distance is added to a reply signal sent forth from the ship to the fixed ground station. The fixed ground station measures an interval between a point of time at which the interrogation signal was issued and a point of time at which a reply signal from the ship was received, thereby defining the position of the ship from said time interval and data on the ship-to-bank distance.

Abstract: A foreground subject-identifying apparatus comprises a sweep signal generator for issuing a sweep signal having frequencies f.sub.s falling within a prescribed range; a carrier wave generator for producing a carrier wave having a frequency f.sub.0 ; a first frequency mixer for mixing output signals from the sweep signal generator and carrier wave generator to generate an output signal having a frequency f.sub.0 .+-.f.sub.s ; a first antenna through which to transmit an output signal from the first frequency mixer; a second antenna mounted on the foreground subject to receive an output signal sent forth from the first antenna; a coding circuit carried on the foreground subject which is provided with a plurality of resonance circuits resonating at different frequencies f.sub.T and adapted to form a specified code from a combination of these different resonance frequencies; a signal mixer for detecting an output signal from the second antenna to supply a signal having frequencies f.sub.