We have developed an ultrafast imaging system to record and observe the femtosecond phenomena in air and an optical medium as a form of a temporally continuous motion picture. To obtain the motion picture, the light-in-flight recording by holography using a femtosecond pulsed laser is applied. We demonstrate the recording and observation of femtosecond laser pulse propagating in air and a dispersion prism. The time and spatial behavior of such femtoseconed light pulse in the prism and at the boundary between the prism and air is clearly observed. This technology achieves a temporal microscope with more than 1011 magnification.
This paper deals with power penalties in Optical Tandem Single Sideband system using orthogonal subcarriers due to chromatic dispersion. The upper and lower sideband orthogonality is affected by chromatic dispersion. This phase imbalance causes degradation of quadrature demodulation performance. The effect is demonstrated by a mathematical model and verified by simulation results.
We report a very simple and reliable method for making Self-Assembled Vertical Comb (SAVC) drive actuators by using the standard SOI bulk micro-machining processes. The initial angular offset of the movable combs is prepared by using the process stiction which occurs during drying process after sacrificial release. The optical scanner integrated with SAVC has shown good electrostatic scanning performance of over 1.0-degree static-rotation angle with a typical drive voltage of 20V without any in-use electromechanical failure.
A new natural gradient-based algorithm for a blind deconvolution of blurred images is proposed. In the proposed algorithm, phase spectral constraint condition is newly introduced, and a natural gradient descent method on an amplitude spectrum is applied. The effectiveness of the proposed algorithm is confirmed by comparing with the conventional method.