The present disclosure relates to a semiconductor light emitting device, comprising: a plurality of semiconductor layers, including a first semiconductor layer having a first conductivity, a second semiconductor layer having a second conductivity different from the first conductivity, and an active layer interposed between the first semiconductor layer and the second semiconductor layer, generating light via electron-hole recombination; a first electrode, supplying either electrons or holes to the plurality of semiconductor layers; a second electrode, supplying, to the plurality of semiconductor layers, electrons if the holes are supplied by the first electrode, or holes if the electrons are supplied by the first electrode; a non-conductive distributed bragg reflector coupled to the plurality of semiconductor layers, reflecting the light from the active layer; and a first light-transmitting film coupled to the distributed bragg reflector from a side opposite to the plurality of semiconductor layers with respect to the non-conductive distributed bragg reflector, with the first light-transmitting film having a refractive index lower than an effective refractive index of the distributed bragg reflector.

Semiconductor Light Emitting Device

The present disclosure relates to a semiconductor light-emitting element, which comprises: a first light-emitting part, a second light-emitting part, and a third light-emitting part, wherein each of the light-emitting parts includes multiple semiconductor layers including a first semiconductor layer, an active layer, and a second semiconductor layer, laminated in sequence, the first semiconductor layer having a first conductivity, the active layer generating light through the recombination of an electron and a hole, and the second semiconductor layer having a second conductivity different from the first conductivity; a non-conductive reflecting film which is formed to cover the multiple semiconductor layers and reflects light generated from the active layer; a first electrode which is provided to electrically communicate with the first semiconductor layer of the first light-emitting part and which supplies one of an electron and a hole; a second electrode which is provided to electrically communicate with the second semiconductor layer of the second light-emitting part and which supplies the other of the electron and the hole; and an auxiliary pad formed on the non-conductive reflecting film which covers the third light-emitting part.

Semiconductor light emitting element

A method of filling a trench comprises heating a semiconductor substrate having a trench formed therein and an oxide film formed at least on the sidewall of the trench and supplying an aminosilane gas to the surface of the substrate so as to form a seed layer on the semiconductor substrate, heating the semiconductor substrate having the seed layer formed thereon and supplying a monosilane gas to the surface of the seed layer so as to form a silicon film on the seed layer, filling the trench of the semiconductor substrate, which has the silicon film formed thereon, with a filling material that shrinks by burning, and burning the semiconductor substrate coated by the filling material filling the trench in an atmosphere containing water and/or a hydroxy group while changing the filling material into a silicon oxide and changing the silicon film and the seed layer into a silicon oxide.

Trench-filling method and film-forming system

Certain embodiments provide a method for manufacturing a semiconductor light emitting device, including: providing a first stack film on a first substrate, the first stack film being formed by stacking a p-type nitride semiconductor layer, an active layer having a multiquantum well structure of a nitride semiconductor, and an n-type nitride semiconductor layer in this order; forming an n-electrode on an upper face of the n-type nitride semiconductor layer; and forming a concave-convex region on the upper face of the n-type nitride semiconductor layer by performing wet etching on the upper face of the n-type nitride semiconductor layer with the use of an alkaline solution, except for a region in which the n-electrode is formed.

Semiconductor light emitting device and method for manufacturing the same

PROBLEM TO BE SOLVED: To provide a new semiconductor laser device which is capable of outputting two or more laser beams adjusting their intensity separately. SOLUTION: The semiconductor laser device of this invention is equipped with a semiconductor multilayer film containing an active layer 24, and a first and a second electrode which are used for injecting a current into the active layer 24 to emit laser beams 61 to 64. The active layer 24 is equipped with end surfaces 24a to 24d. The end surfaces 24a to 24d are each located at the four apexes of a virtual diamond-shaped route 32. Laser beams (L1/L2) propagating clockwise and counterclockwise through the route 32 are partially emitted as the laser beams 61 to 64. The first and second electrode are formed so as to inject electric currents, which are different from each other in intensity, into the parts of the active layer 24 which are corresponding to the diamond-shaped route 32 and divided by the diagonal lines of the diamond-shaped route 32. The currents which are injected into the parts of the active layer 24, are changed in intensity, whereby the intensity of the laser beams 61 to 64 are controlled. COPYRIGHT: (C)2008,JPO&INPIT

Semiconductor laser device

A semiconductor fiber-optic ring laser gyroscope, which consist of a semiconductor optical amplifier as a gain medium and polarization-maintaining fiber to form a ring resonator, generate Sagnac beat signals demonstrating good agreement with theoretical calculations.

Sagnac Beat Signals Observed in Semiconductor Fiber-Optic Ring Laser Gyroscope

We are conducting research to confirm the performance of a semiconductor fiber-optic ring laser gyroscope (S-FOG)
featuring a semiconductor in its laser cavity. This S-FOG consists of a semiconductor optical amplifier (SOA) as a gain
medium, a polarization-maintaining fiber to make a ring cavity, and a directional coupler to take part of the optical
power out of the cavity. One of the advantages of the S-FOG is the adaptability of the laser cavity, which allows us to
examine many cases of S-FOG applications easily. In the first case, we observed that the S-FOG generated Sagnac beat
signals whose peak frequency was proportional to the rotation rate when it rotated. In the second case, we changed the
area surrounded by the ring cavity (the fiber) and its perimeter and maintained a near-fixed oscillation wavelength of the
ring laser. In this case, all of our experimental results were in good agreement with theoretical calculations, within a few
percent. In the third case, we changed the oscillation wavelength and fixed the shape of the ring cavity. In this case, our
results were also in good agreement with theoretical calculations. In the fourth case, we examined the Sagnac beat
spectrum generated by the S-FOG in detail. The linewidth of the Sagnac beat spectrum increases as the area bounded by
the optical path in the ring cavity becomes smaller, or as the length of the cavity becomes shorter. Our experimental
results show that the S-FOG works as a gyro and that there exists practical potential for a semiconductor ring laser gyro.

Experimental investigation of Sagnac beat signals using semiconductor fiber-optic ring laser gyroscope (S-FOG) based on semiconductor optical amplifier (SOA)

A laser gyro of the present invention includes laser light excitation means (a semiconductor laser device 100 ) that excites first and second laser lights propagating in the opposite directions to each other in a circular ring-shaped path (an optical path 40 ), coupling means (optical waveguides 41 and 42 ) for superimposing the first and the second laser lights, and a photodetector for observing an interference signal generated by the superimposed first and second laser lights.

Laser gyro and electronic device using the same

A semiconductor fiber-optic ring laser gyroscope (S-FOG) consists of a semiconductor optical amplifier (SOA) and optical fiber to form a ring cavity. The fiber ring cavity enables larger sizes and smaller scattering, while the SOA gain is shared by the clockwise (CW) and counterclockwise (CCW ) propagating modes. When the S-FOG is rotated, a new beat signal called the Sagnac beat frequenc y is observed. We investigated the effect of the fiber ring cavitys length on detection characteristics. Detection sensitivity was not depende nt on the number of laps of fiber ring cavity. However, when the cavity length became longer, the linewidth of Sagnac beat became narrower, and then accuracy of angular velocity detection improved. The relation between the linewidth ' Q of the Sagnac beat and cavity length P was proved to be ' Q | P -1.86 . Keywords : Sagnac effect, laser gyroscope, S-FOG, lin ewidth, beat frequency, scale factor, SOA 1. INTRODUCTION Since a gyroscope measures angular velocity, it is used for inertial guidance and control applications [1]. Optical gyros based on the Sagnac effect are well known for their high performance. Two types of optical gyros are commonly used. One is the fiber optic gyro (FOG), which is formed by surrounding a coil with optical fiber [2]. The other is the ring laser gyro (RLG), which is formed by a He-Ne gas lase r and a ring resonator in plural mirrors [3]. These gyros have a miniaturization limit due to the use of optical fiber for the FOG; furthermore, they have a low cost limit because a conventional RLG using a He-Ne laser requires high precision mirrors. As a new type of RLG, we proposed a semiconductor fiber-optic ring laser gyroscope (S-FOG) that consists of a semiconductor optical amplifier (SOA) and polarization-maintaining optical fiber to form a ring cavity [4]. Through experiments on S-FOG we observed the beat frequencies of counter-propagating light inside a semiconductor fiber-ring laser due to the Sagnac effect. However, we have not yet evaluated the performance of S-FOG. On performance of the RLG, it has been considered that the frequency difference between CW and CCW propagating lights do not depend on the total length of the cavity so an increased scale factor is not achieved by using long fiber optic coils in active ring laser gyros [2,3]. Even if the length of the ring cavity becomes longer, the sensitivity of the RLG does not increase. Therefore the cavity length is not related to performance of the RLG. However, we confirmed that when the cavity length becomes longer, performance of the RLG improves independent of the scale factor. In this paper, we evaluate the performances of the gyrosc ope. The linewidth of the Sagna c beat spectra is a parameter that expresses the accuracy of angular ve locity detection, and the narrow linewidth of the beat spectrum indicates high accuracy detection. Through experiments on S-FO G, we show that while detecti on sensitivity does not depend on the cavity length, the Sagnac beat spectral linewidth does. As the cavity length becomes longer, the linewidth of Sagnac beat becomes narrower, and then accuracy of angular velocity detection improves. Moreover , we show that the relation between the linewidth of the Sagnac beat and the cavity length.

Takahisa Harayama

Papers

Semiconductor laser device

Sagnac Beat Signals Observed in Semiconductor Fiber-Optic Ring Laser Gyroscope

Experimental investigation of Sagnac beat signals using semiconductor fiber-optic ring laser gyroscope (S-FOG) based on semiconductor optical amplifier (SOA)

Laser gyro and electronic device using the same

Improvement of accuracy of angular velocity detection in semiconductor fiber-optic ring laser gyroscope