Anritsu Corporation

Tomoyuki Kikugawa

Yasuaki Nagashima

Hiroshi Mori

Atsushi Yamada

Yoshiharu Shimose

Youji Sonobe

Yoshio Takahashi

Motoaki Fujita

Katsunori Shinone

Yoshinori Nakano

Yasuhiro Kanaya

Seiichi Ishigaki

A semiconductor laser includes a substrate made of InP, an active layer including a multiquantum well structure, which is formed in a width of 7 to 14 &#x3bc;m on the substrate, and an n-type cladding layer made of InGaAsP and a p-type cladding layer made of InP, which are formed on the substrate with the active layer interposed therebetween. The semiconductor laser oscillates only in the fundamental lateral mode, and light emitted from an exit facet can be optically coupled with an external single mode optical fiber.

Semiconductor laser capable of coupling with single mode optical fiber at high coupling efficiency

First and second diffraction grating layers are provided above a semiconductor substrate, and are spaced from each other in an output direction of a beam with a flat connecting layer sandwiched therebetween. An active layer is disposed above or below the first and second diffraction grating layers and the connecting layer. A cladding layer is disposed above the active layer or above the first and second diffraction grating layers and the connecting layer. A diffraction grating including the first and second diffraction grating layers has a plurality of slits penetrating from an upper surface to a lower surface that are perpendicular to the output direction of the beam. The connecting layer is formed from two layers grown epitaxially in a direction perpendicular to the output direction of the beam. One of the two layers is formed of the same material as the first and second diffraction grating layers.

Distributed feedback semiconductor laser for outputting beam of single wavelength

The semiconductor light emitting device includes a semiconductor substrate formed from InP, an active layer, an n-type cladding layer formed from InGaAsP, and a p-type cladding layer formed from InP. The active layer is formed at the upper side of the semiconductor substrate. The n-type cladding layer and the p-type cladding layer are formed so as to hold the active layer therebetween. The semiconductor light emitting device is, given that, a refractive index of the n-type cladding layer is na, and a refractive index of the p-type cladding layer is nb, set so as to be the relationship of na&#x3e;nb in which the refractive index na of the n-type cladding layer is higher than the refractive index nb of the p-type cladding layer, and due to the distribution of light generated by the active layer being deflected to the n-type cladding layer side, optical loss by intervalence band light absorption at the p-type cladding layer is suppressed, and high-power light output can be obtained.

Semiconductor light emitting device in which high-power light output can be obtained with a simple structure including InGaAsP active layer not less than 3.5 microns and InGaAsP and InP cladding

An n-type semiconductor substrate has a ( ) crystal plane as an upper surface. A mesa stripe portion has a trapezoidal shape including an n-type first clad layer, an active layer and a p-type second clad layer sequentially stacked on the substrate and formed along a <011> direction. A current block portion has a p-type current blocking layer and an n-type current blocking layer. A p-type third clad layer simultaneously covers both the upper surfaces of the mesa stripe portion and the current blocking portion. The inclination angle as being acute angle of the side surface of the mesa stripe portion is close to the inclination angle of a ( )B crystal plane with respect to the ( ) crystal plane and set at one of an angle larger than and an angle smaller than the inclination angle of the ( )B crystal plane.

Semiconductor laser attaining high efficiency and high power, and method of manufacturing the same

Disclosed is a semiconductor laser capable of preventing diffusion of a p-type dopant to an active layer while performing sufficient carrier blocking, even when Zn is used as a p-type dopant, and obtaining high emission efficiency and high output by minimizing light absorption in a p-type cladding layer. This semiconductor laser includes an active layer and p-type cladding layer on an n-type semiconductor substrate. The concentration distribution of a p-type dopant from the active layer to the p-type cladding layer has a maximum value at a distance of 50 to 250 nm from the end of the active layer.

Semiconductor laser having effective output increasing function

In an optical measuring apparatus, a laser beam is transferred to a diffraction grating so that the laser beam is spectrally separated into respective wavelength components. The wavelength components are sequentially guided into a polarizing optical element in which the respective wavelength component are separated into S and P polarized components, when the diffraction grating is rotated. The S and P polarized components of the respective wavelengths are detected by photodetectors and electrical signals from the photodetectors are supplied to a signal processing unit. In the signal processing unit, the electrical signals corresponding to the P and S components are corrected with a spectral efficiency characteristic of the grating, a percent loss characteristic of the polarizing element and photoelectro conversion characteristics of the photodetectors and the corrected signals are analyzed to obtain an absolute value of the laser energy for the respective wavelength.

Growing community of inventors

Atsugi, Japan

Tomoyuki Kikugawa