Anritsu Corporation

Muneo Ishiwata

Yasuaki Nagashima

Hiroaki Endoh

Hiroaki Endo

Takao Tanimoto

Hiroaki Ohtateme

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.

Tunable wavelength light source apparatus for stabilizing power

A sawtooth generates a sawtooth wave having a high response speed and good linearity with a simple arrangement in converting a change in phase of an input signal into a linear level change. A signal interpolating apparatus uses this sawtooth wave to output a predetermined signal (interpolation signal) every predetermined phase change of the input signal with a simple arrangement. An arithmetic operation section receives two sinusoidal signals A and B having equal periods and phases which are offset by 90.degree. and with respect to each other, obtain a signal X=A/(B+a) and a signal Y=A/(B+B) using constants .alpha. and .beta. respectively satisfying B+.alpha..apprxeq.0 and B+.beta..apprxeq.0. A switching unit selects the linear ramp portions of the signals X and Y to output a continuous sawtooth wave. On the basis of the value of this sawtooth wave, a desired interpolation signal is output from a memory which stores predetermined data.

Growing community of inventors

Minami-ashigara, Japan

Muneo Ishiwata