摘要:
A semiconductor laser device including an n-type cladding layer, an active layer, a p-type cladding layer having a ridge portion, an n-type optical confinement layer formed on the flat portion and side surfaces of the ridge portion of the p-type cladding layer, and an n-type current blocking layer formed on the n-type optical confinement layer in this order. The optical confinement layer is composed of a low resistivity layer doped with n-type impurity, which has a smaller refractive index than the p-type cladding layer and a bandgap energy greater than the energy of lasing light. The optical confinement layer has an impurity concentration of 5.times.10.sup.7 cm.sup.-3 or less. The n-type current blocking layer has a thickness of 0.4 .mu.m or less.
摘要翻译:一种半导体激光装置,包括n型包层,有源层,具有脊部的p型包覆层,形成在平坦部分上的n型光限制层和p型包层, 型包层,以及n型光限制层上形成的n型电流阻挡层。 光限制层由掺杂有n型杂质的低电阻率层构成,其折射率比p型覆层更小,并且带隙能量大于激光的能量。 光学限制层的杂质浓度为5×10 7 cm -3以下。 n型电流阻挡层的厚度为0.4μm以下。
摘要:
A semiconductor laser with a self-sustained pulsation is disclosed in which a first cladding layer of first conductive type, an active layer and a second cladding layer of second conductive type having a striped ridge are formed in that order on a semiconductor substrate of first conductive type. The first and second cladding layers have a refractive index smaller than and a band gap larger than the active layer. A saturable optical absorbing layer having a band gap of energy substantially equal to the energy corresponding to lasing wavelength is formed in both the first and second cladding layers. Further, a barrier layer having a refractive index smaller than and a band gap larger than the first and second cladding layers is formed between the first cladding layer and the active layer and/or between the active layer and the second cladding layer.
摘要:
A semiconductor laser with a self-sustained pulsation is disclosed in which a first cladding layer of first conductive type, an active layer and a second cladding layer of second conductive type having a striped ridge are formed in that order on a semiconductor substrate of first conductive type. The first and second cladding layers have a refractive index smaller than and a band gap larger than the active layer. A saturable optical absorbing layer having a band gap of energy substantially equal to the energy corresponding to lasing wavelength is formed in both the first and second cladding layers. Further, a barrier layer having a refractive index smaller than and a band gap larger than the first and second cladding layers is formed between the first cladding layer and the active layer and/or between the active layer and the second cladding layer.
摘要:
A semiconductor laser with a self-sustained pulsation is disclosed in which a first cladding layer of first conductive type, an active layer and a second cladding layer of second conductive type having a striped ridge are formed in that order on a semiconductor substrate of first conductive type. The first and second cladding layers have a refractive index smaller than and a band gap larger than the active layer. A saturable optical absorbing layer having a band gap of energy substantially equal to the energy corresponding to lasing wavelength is formed in both the first and second cladding layers. Further, a barrier layer having a refractive index smaller than and a band gap larger than the first and second cladding layers is formed between the first cladding layer and the active layer and/or between the active layer and the second cladding layer.
摘要:
In a semiconductor laser device comprising an n-type cladding layer, an active layer formed on the cladding layer, a p-type cladding layer formed on the active layer, and a p-type saturable light absorbing layer provided in the p-type cladding layer, the current confinement width for confining current injected into the active layer being W, the thickness d.sub.a of the active layer, the optical confinement factor .GAMMA..sub.a of the active layer, the thickness d.sub.s of the saturable light absorbing layer, the optical confinement factor .GAMMA..sub.s of the saturable light absorbing layer, and the light spot size S on a facet of the semiconductor laser device are so set as to satisfy a predetermined relationship. The reflectivity on a light output facet is set in the range of 10 to 20%.
摘要:
In an optical pickup apparatus, a laser beam emitted from a semiconductor laser device is reflected upward by a reflecting member, transmitted through a transmission type diffraction grating and split into at least three beams, and which beams are transmitted through a transmission type holographic optical element and condensed onto an optical recording medium by a condenser portion. A return beam reflected by the optical recording medium passes through the condenser portion and diffracted not to impinge upon the transmission type diffraction grating by the holographic optical element and directed to a photodetector portion of a light receiving device. The semiconductor laser device and the light receiving device are disposed in a mount member. The transmission type holographic optical element is supported by a supporting member three-dimensionally movably with respect to the mount member, and the supporting member or/and the holographic optical element is/are fixed with adhesive material with the transmission type holographic optical element being positioned with respect to the mount member.
摘要:
A transmission-type holographic optical element has a four-segment holographic surface divided into four regions of equal areas by virtual dividing lines which are perpendicular to each other. The first dividing line is at an angle with respect to the track direction of an optical disk and the second dividing line is at an angle with respect to the radial direction of the optical disk before tracking phase adjustment. The first dividing line coincides with the track direction of the optical disk and the second dividing line coincides with the radial direction of the optical disk after tracking phase adjustment. A four-segment photodetection part is divided into four photodetection parts of equal areas by a dividing line substantially parallel to the radial direction of the optical disk and a dividing line perpendicular thereto. Parts of a main beam diffracted in two regions located on first diagonal positions of the four-segment holographic surface are condensed as condensed spots on adjacent positions of the first dividing line of the four-segment photodetection part on opposite sides, and parts of the main beam diffracted in the remaining two regions located on second diagonal positions are condensed as condensed spots on separate positions of the second dividing line of the four-segment photodetection part on opposite sides.
摘要:
First and second photodiodes are arranged on the upper surface of a stem, returned light beams diffracted in the + 1st order by a transmission type holographic optical element are received by the first photodiode, while returned light beams diffracted in the − 1st order are received by the second photodiode. The first photodiode has a plurality of light receiving regions, and respectively outputs a reproducing signal, a focus error signal and a tracking error signal on the basis of the returned light beams. On the other hand, the second photodiode has a single light receiving region, and outputs a reproducing signal on the basis of the returned light beams.
摘要:
A grating surface of a diffraction grating diffracts a laser beam emitted from a semiconductor laser device in ±1st order directions. The grating surface is formed in a rectangular or elliptic shape in such dimensions that a light spot formed on an objective lens by ±1st order diffracted beams is located in an aperture of the objective lens and not displaced from the aperture even if the objective lens is horizontally moved in a tracking operation. A grating surface of another diffraction grating has a width smaller than the width of an overlap region of a light spot on the diffraction grating corresponding to a part of a beam, diffracted in the +1st direction, entering an objective lens and a light spot on the diffraction grating corresponding to a part of a beam, diffracted in the −1st direction, entering the objective lens.
摘要:
A method of manufacturing a surface-emitting-type semiconductor laser device having a buried structure. A GaAlAs film is used as a mask layer in forming a GaAlAs/GaAs system burying part around a GaAlAs/GaAs system buried part. The mask layer can be formed continuously together with an active layer, a cladding layer and the like which constitute the buried part by means of a crystal growing apparatus for forming the buried part. When the system is etched, the GaAlAs film mask prevents the system buried part from becoming undercut so that the mask has better resistance to peeling during subsequent processing.