All issues
Volume 36, Issue 10
Displaying 1-9 of 9 articles from this issue
- |<
- <
- 1
- >
- >|
-
Osamu MATOBA2008 Volume 36 Issue 10 Pages 606
Published: October 15, 2008
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSDownload PDF (202K) -
Hiroyuki ICHIKAWA2008 Volume 36 Issue 10 Pages 607-613
Published: October 15, 2008
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSAnalyzing behaviour of light as electromagnetic wave is nowadays very important in many fields in optics and photonics. This trend has been accelerated by development of fabrication technology down to nano-scale. One of the most popular numerical tools for that task is the finite-difference time-domain (FDTD) method. This review explains the essence of the FDTD method from the basic so that absolute beginners can understand the subject and will be able to use the FDTD method for various applications including optical elements, plasmonic, metamaterials, near field optics, ultrafast phenomena, terahertz waves, laser processing and biomedical optics in the near future.View full abstractDownload PDF (8173K) -
Satoshi IWAMOTO, Yasuhiko ARAKAWA2008 Volume 36 Issue 10 Pages 614-620
Published: October 15, 2008
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSPhotonic crystals, which are artificial optical materials consisting of periodic dielectric modulations, enable one to control lightwave in nanostructures. Optical waveguide with sharp bending and high-Q nanocavity are now available. Because of their complicated structure and high index contrast, numerical design or simulation are necessary and play crucial roles in the researches using photonic crystals. In this review, we describe how to apply FDTD method for designing photonic crystal nanocavities and show examples from our experimental researches where FDTD simulation plays important roles. Finally, we will briefly introduce frequency-dependent FDTD method for analyzing photonic crystals with quantum dots as gain mediaView full abstractDownload PDF (13248K) -
Yasuyuki OKAMURA2008 Volume 36 Issue 10 Pages 621-627
Published: October 15, 2008
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSA pseudo-spectral time-domain method, abbreviated as PSTD method, plays an important role in analyzing many kinds of scientific and engineering fields, especially large scale area problems such as weather forecast and scattering. The employment of the PSTD method is owed to the usage of the fast Fourier transform (FFT) for the spatial derivatives of Maxwell's equations. In this paper we discuss the PSTD method for the electromagnetic transient problem and its application to the analysis of optical waveguides with a long periodic grating, and show the experimental result for the waveguides fabricated based on the PSTD method discussed here.View full abstractDownload PDF (13848K) -
Tetsuro YABU2008 Volume 36 Issue 10 Pages 628-634
Published: October 15, 2008
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSThe beam Propagation Method (BPM) is one of the most common methods for analyzing optical waveguides. Its calculation speed is much faster than other methods, such as FDTD. However, the scope of its applications is limited. BPM is applicable when the following two assumptions are satisfied: 1) lightwaves propagate along a certain axis; 2) reflection can be ignored. In this paper, theoretical fundamentals of BPM is precisely explained to enable readers to understand the scope of its applications. Then, BPM formulations in nonlinear materials are derived.View full abstractDownload PDF (1371K) -
Kashiko KODATE2008 Volume 36 Issue 10 Pages 635-642
Published: October 15, 2008
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSThe field of diffractive optical elements has a long history, and various fabrication methods have been developed over time. Recent progress in nanotechnology further facilitated fabrication of diffractive optical elements with a periodic structure that has less than one wavelength. In the case of this type of element (e. g. device structure of which the size is less than one wavelength or a deep trench that is several times longer than its wavelength), a rigorous method is required for analyzing polarization, evanescent waves and beam propagation inside grating structures. This paper provides a brief overview of numerical methods for electromagnetic wave analysis, with particular focus on the difference between the Finite-Difference Time-Domain (FDTD) Method and Rigorous Couple-Wave Analysis (RCWA). The latter method is suitable for analyzing diffractive optical elements with binary sub-wavelength structures and Volume Phase Holographic (VPH) gratings. Furthermore, the paper introduces the authors' numerical analysis based on RCWA, underlining its merit and applications to design and evaluation of diffractive optical elements.View full abstractDownload PDF (3008K) -
Taku SAIKI, Kazuhisa HASHIMOTO, Shinji MOTOKOSHI, Kazuo IMASAKI, Hisan ...2008 Volume 36 Issue 10 Pages 643-647
Published: October 15, 2008
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSA laser beam passes through 12 or 24 circular apertures arranged annularly, and the transmitted beams overlapped with each other in phase to generate a Bessel beam. The resultant beam propagates and maintains characteristic narrow energy distribution that agrees with the results of numerical calculation.View full abstractDownload PDF (12464K) -
Hiroaki YOSHIOKA, Shinki NAKAMURA, Takayo OGAWA, Satoshi WADA2008 Volume 36 Issue 10 Pages 648-652
Published: October 15, 2008
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSAhigh-power efficient ceramic Yb: YAG laser was demonstrated at room temperature of 20°C with a Yb concentration of 9.8 at.%, a gain medium of 1mm, pumping power of 13.8W, an output coupler of T=10%, and a cavity length of 20mm. 6.8W cw output power was obtained with a slope efficiency of 72%. The ceramic Yb: YAG laser exhibited continuous tunability in a spectral range of 118.31nm from 992.52 to 1110.83 nm for T=0.1%. This is the broadest tunability on Yb: YAG lasers.View full abstractDownload PDF (5276K) -
Chihiro MORIGUCHI, Chikara EGAMI, Yoshimasa KAWATA, Masaaki TSUCHIMORI ...2008 Volume 36 Issue 10 Pages 653-657
Published: October 15, 2008
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSWe demonstrated observation of glycerinated muscle with near-field recording technique that we have developed. Using this technique, optical field distributions localized near specimens are recorded as surface topographic distributions of a photosensitive film. The topographic distribution is detected with a high resolution microscope such as AFM. The technical system is no requirement to scan the optical probe for illuminating the sample or detecting the light localized near the specimen. Furthermore, the system can observed moving or soft specimens. We show that striped periodic structures of muscle cell before and after muscle contraction and lengths of each inner structure of muscle cell such as A-band, I-band, and Z-line can be measured with wavelength resolution. Our technique can achieve higher contrast and the periodic structure of glycerinated muscles was clearly observed compared to conventional optical microscope image.View full abstractDownload PDF (9864K)
- |<
- <
- 1
- >
- >|