Publications by authors named "Daisuke Sakaizawa"

We report performance of a satellite-borne coherent Doppler wind lidar (SCDWL), which equips a planer waveguide amplifier (PWA) operating in a wavelength of 1.5 µm. The performance is defined by detection probability, measurement precision, and bias, and is characterized with a Doppler wind lidar (DWL) simulation that considers a realistic wind velocity profile, and instrumental and atmospheric parameters.

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We demonstrate a master oscillator power amplifier (MOPA) system that emits single-frequency high-energy optical pulses at 1540 nm using an Er,Yb:glass planar waveguide amplifier and a large mode area Er-doped fiber amplifier. A double under-cladding and a 50-µm-thick core structure are employed for the planar waveguide amplifier to increase the output energy without degrading the beam quality. A pulse energy of 45.

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We have demonstrated the laser-absorption spectrometer system using frequency chirped intensity modulation at 1.57 μm wavelength for measurement of CO(2) concentration. Using this technique, backscattered laser radiation from different ranges can be discriminated in the frequency domain of the electrical signal.

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A feasibility study is carried out on a 1.6 μm continuous-wave modulation laser absorption spectrometer system for measurement of global CO(2)concentration from a satellite. The studies are performed for wavelength selection and both systematic and random error analyses.

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In a previous study, we developed a 1.6 μm continuous-wave (cw) modulation laser absorption spectrometer system for CO(2) sensing and demonstrated the measurement of small fluctuations in CO(2) corresponding to a precision of 4 parts per million (ppm) with a measurement interval of 32 s. In this paper, we present the process to achieve this highly specific measurement by introducing important points, which have not been shown in the previous study.

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We have demonstrated the 1.6 mum cw modulation hard-target differential absorption lidar system for CO(2) sensing. In this system, ON and OFF wavelength laser lights are intensity modulated with cw signals.

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We have developed a 1.6 microm carbon dioxide (CO(2)) differential absorption lidar utilizing a quasi-phase-matching optical parametric oscillator (OPO) and a photon-counting detector. The operating wavelengths were chosen based on their low interference from water vapor and low temperature sensitivity.

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