Masamichi Yamanishi

Publications (142) View all

• Source

  Available from: Saverio Bartalini

  Article: Subkilohertz linewidth room-temperature mid-infrared quantum cascade laser using a molecular sub-Doppler reference.

  F Cappelli, I Galli, S Borri, G Giusfredi, P Cancio, D Mazzotti, A Montori, N Akikusa, M Yamanishi, S Bartalini, P De Natale
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  ABSTRACT: We report on the narrowing of a room-temperature mid-IR quantum cascade laser by frequency locking it to a CO₂ sub-Doppler transition obtained by polarization spectroscopy. A locking bandwidth of 250 kHz has been achieved. The laser linewidth is narrowed by more than two orders of magnitude below 1 kHz, and its absolute frequency is stabilized at the same level.
  Optics Letters 12/2012; 37(23):4811-3. · 3.40 Impact Factor
• Article: Extremely temperature-insensitive continous-wave quantum cascade lasers

  K. Fujita, M. Yamanishi, S. Furuta, A. Sugiyama, T. Edamura
  Applied Physics Letters 10/2012; · 3.84 Impact Factor
• Source

  Available from: Davide Mazzotti

  Article: Measuring frequency noise and intrinsic linewidth of a room-temperature DFB quantum cascade laser.

  S Bartalini, S Borri, I Galli, G Giusfredi, D Mazzotti, T Edamura, N Akikusa, M Yamanishi, P De Natale
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  ABSTRACT: The frequency-noise power spectral density of a room-temperature distributed-feedback quantum cascade laser emitting at λ = 4.36 μm has been measured. An intrinsic linewidth value of 260 Hz is retrieved, in reasonable agreement with theoretical calculations. A noise reduction of about a factor 200 in most of the frequency interval is also found, with respect to a cryogenic laser at the same wavelength. A quantitative treatment shows that it can be explained by a temperature-dependent mechanism governing the transport processes in resonant tunnelling devices. This confirms the predominant effect of the heterostructure in determining shape and magnitude of the frequency noise spectrum in QCLs.
  Optics Express 09/2011; 19(19):17996-8003. · 3.59 Impact Factor
• Source

  Available from: Masamichi Yamanishi

  Article: Frequency-Noise Dynamics of Mid-Infrared Quantum Cascade Lasers

  S. Borri, S. Bartalini, P.C. Pastor, I. Galli, G. Giusfredi, D. Mazzotti, M. Yamanishi, P. De Natale
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  ABSTRACT: By measuring the frequency-noise power spectral density of a cryogenically-cooled mid-infrared quantum cascade laser, we investigate the different contributions to the noise spectrum and identify the main differences with respect to standard bipolar semiconductor devices. In particular, the existence of a thermal cut-off on the 1/f noise allows to identify the current fluctuations through the heterostructure as the physical mechanism, intrinsic to the device, at the basis of the measured flicker noise. This result, marking the difference with bipolar semiconductor devices, is confirmed analyzing the laser frequency response to a modulation of the driving current.
  IEEE Journal of Quantum Electronics 08/2011; · 1.88 Impact Factor
• Source

  Available from: Romain Blanchard

  Article: Dipolar modeling and experimental demonstration of multi-beam plasmonic collimators

  J-P Tetienne, R Blanchard, N Yu, P Genevet, M A Kats, J A Fan, T Edamura, S Furuta, M Yamanishi, F Capasso
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  ABSTRACT: We designed a new class of plasmonic gratings that generate multiple free-space beams in arbitrary directions from a point source of surface waves, using a phenomenological model that accurately predicts their far-field, in amplitude, phase and polarization. We fabricated such gratings on the facets of semiconductor lasers. The plasmonic gratings proposed here are generally relevant to the interfacing of nanoscale optical components to free-space beams. The model introduced here can be used to design general two-dimensional plasmonic gratings.
  New Journal of Physics 01/2011; 13:53057. · 4.18 Impact Factor