Anritsu Corporation

Yasuaki Nagashima

Tomoyuki Kikugawa

Hiroshi Mori

Atsushi Yamada

Muneo Ishiwata

Yoshiharu Shimose

Hiroaki Endo

Takao Tanimoto

Hiroaki Ohtateme

Hiroaki Endoh

Shintaro Morimoto

Katsunori Shinone

Yoshinori Nakano

Yasuhiro Kanaya

[Task] To provide a semiconductor light emitting element capable of emitting light beams with wavelengths in a plurality of wavelength ranges with a high optical output, a driving method of a semiconductor light emitting element capable of making a semiconductor light emitting element that can emit light beams with wavelengths in a plurality of wavelength ranges operate with a high optical output, a light emitting device, and a small and high-performance optical pulse tester using the light emitting device. [Means for Resolution] In a driving method of a semiconductor light emitting element with a configuration in which an active layerwith a gain wavelength &#x3bb;of about 1.55 &#x3bc;m and an active layerwith a gain wavelength &#x3bb;of about 1.3 &#x3bc;m are optically coupled along the guiding direction of light and are disposed in series in order of the length of the gain wavelengths &#x3bb;and &#x3bb;and a diffraction gratingwith a Bragg wavelength of the short gain wavelength &#x3bb;is formed near the active layerwith the short gain wavelength &#x3bb;and near a butt-joint coupling portionbetween the active layersand, an upper electrode provided above the active layeris short-circuited to a lower electrode provided on a bottom surface of a semiconductor substrate so that a leakage current does not flow into the active layerwhen a driving current is applied to the active layer

Semiconductor light emitting element, driving method of semiconductor light emitting element, light emitting device, and optical pulse tester using light emitting device

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

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

A processing unit reads out, from a memory, wavelength setting data corresponding to wavelength information from a key input section, and outputs a wavelength setting command corresponding to the wavelength setting data to a tunable-wavelength control section and a spectral wavelength control section. The tunable-wavelength control section controls a tunable-wavelength light source section to output a laser beam having a wavelength corresponding to the wavelength setting data. The spectral wavelength control section controls a spectroscope section to perform spectroscopy of the light having the wavelength corresponding to the wavelength setting data and output the resultant light. Output light from the tunable-wavelength light source section whose wavelength has been set is input to an object to be measured. Light passing through the object is input to the spectroscope section. The spectroscope section performs spectroscopy of only the light having the wavelength corresponding to the wavelength setting data. A light-receiving section receives the spectral light and photoelectrically converts it. The resultant light is converted into digital data by an A/D conversion section to be input as level data to a processing unit. The processing unit obtains a light-reception level on the basis of the digital level data.

Optical transmission characteristic measuring apparatus and calibration

To obtain a predetermined power intensity without influencing the wavelength of output light by external APC, a laser beam having a predetermined plane of polarization and output from a tunable wavelength light source passes through a Faraday element and a polarizer constituting an optical attenuator and is split into a split light beam and an output light beam by a beam splitter. The split light beam is received by a light-receiving device, and a detection signal according to the power intensity is output from the light-receiving device. A controller supplies a signal according to the difference between the detection signal output from the light-receiving device and a set value set at an intensity setting device to a coil of the Faraday element constituting the optical attenuator. The plane of polarization of the laser beam output from the Faraday element is rotated with respect to the plane of polarization of the polarizer, thereby controlling the attenuation amount of the optical attenuator such that the detection signal output from the light-receiving device always equals the set value.

Growing community of inventors

Atsugi, Japan

Yasuaki Nagashima