Seiji Fukushima

Electro-absorption modulator integrated laser application to a cube satellite earth station

Because of mission extensions, a cube satellite uses several frequencies and its earth station suffers from cabling around antennas. We report an earth station employing an electro-absorption modulator integrated laser in a RoF system.

Flat retroreflector based on transformation electromagnetics

A flat reflector having retroreflection characteristics is presented based on transformation electromagnetics. The retroreflector is designed with a distributed full-tensor anisotropic metamaterial. Its retroreflection operations are confirmed by circuit simulations based on the equivalent circuit model of the distributed anisotropic metamaterial.

Metal-complex-doped polymer/liquid-crystal composite film operating at wide wavelength range

Doping metal complex into polymer liquid-crystal composite film improves extinction ratio at visible wavelength and extends applicable wavelength to 1.5-μm optical fiber communication band. A polarization dependent loss was measured as 0.32 dB or lower.

The Improved 16th-Order Differential Attack on 10- Round Variant of Block Cipher PRESENT

We study the improved 16th-order differential attack on 10-round variant of PRESENT that is a 64-bit block cipher supporting 80-bit and 128-bit secret keys proposed by Bogdanov et al. in 2007. Higher-order differential attack is one of the cryptanalytic techniques exploiting a low algebraic degree of an encryption/decryption function. In 2013 Wu et al. reported the 16th-order differential attack on 10-round variant of PRESENT, which requires 222.4 pairs of plaintext and ciphertext, and 299.3 times of encryption operation. In this article we adopt partial sum technique to solve an attack equation, which leads to low computational complexity. As a result we show that 10-round variant of PRESENT can be attacked with 222.3 pairs of plaintext and ciphertext, and 281.3 times of encryption operation.

Variable optical attenuator employing a dye-doped (polymer/liquid crystal) composite film

To clarify extinction mechanism of a dye-doped (polymer/liquid crystal) composite film variable optical attenuator, we evaluated its scattering intensity dependencies on the wavelength and scattering angle. We have obtained some experimental data that suggest Rayleigh scattering is a primary mechanism of extinction.

Demonstration Of An Asynchronous Transfer Mode Switch Using A 10-gbit/s Serial Optical Interconnection

ThQl Fig. 3. Bit error rates for an analog non-linear opto-electronic repeater with different non-linearities. The calculation only considers the signal levels, so jitter and other timedependent effects are not taken into consideration. Therefore, y = 0 will correspond to a system where the signals are digitally regenerated. The non-linear function is a step function when y = 0 that continuously transfer into a linear function when y is increased to 1.

Direct image transmission through a multimode fiber using an optically addressed spatial light modulator

Direct image transmission through a multi-mode fiber is demonstrated using an optically addressed spatial light modulator as a phase conjugation mirror with an image-input function.