1-3hit |
Yu SUGITA Yoshifumi TAKASAKI Keiji KURODA Yuzo YOSHIKUNI
A Fourier domain optical coherence tomography system for obtaining a two-dimensional image is constructed. Imaging characteristics of the OCT system in a transverse direction are experimentally investigated. Angle dependence of reflection intensity from a smooth surface is clearly observed and analyzed with consideration of spatial mode coupling to a fiber.
Takaaki KAKITSUKA Shinji MATSUO
We present a novel high-speed transmitter consisting of a frequency modulated DBR laser and optical filters. The refractive index modulation in the phase control region of the DBR laser allows high-speed frequency modulation. The generated frequency modulated signal is converted to an intensity modulated signal using the edge of the optical filter pass band. We present theoretical simulations of high-speed modulation characteristics and extension of transmission reach. With the proposed transmitter, we review the experimental demonstration of 180-km transmission of a 10-Gb/s signal with a tuning range of 27 nm and 60-km transmission of a 20-Gb/s signal.
Yukio KATOH Koji YAMADA Tatsuo KUNII Yoh OGAWA
A wavelength tunable DBR laser monolithically integrated with an EA-modulator as a WDM system light source was fabricated by selective area MOVPE growth. The lasing wavelength and band-gap energy were simultaneously controlled on the same epitaxial wafer by using a modulated grown thickness of InGaAsP/InGaAsP MQW layers. A wavelength tuning range of 3.5 nm, an output power of 3 mW, and an extinction ratio of 14 dB for 3 V were achieved. The measured 3 dB frequency bandwidth was 2 GHz. No significant change in modulation characteristics were observed when wavelength tuning by injecting the current into the DBR.