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Hiroshi Yamazaki

Publications and source records attributed to Hiroshi Yamazaki.

4 recordsLinked to original sources

Frequency-switching Coherent Reception for Hardware-efficient High-baud-rate Optical Transmission Experiments

We investigate frequency-switching coherent reception (FSCR), a hardware-efficient technique for offline coherent optical signal characterization in laboratory environments, enabling bandwidth extension without costly and hardware-intensive parallel receiver architectures. By combining signal gating and local-oscillator frequency switching, FSCR captures multiple spectral slices sequentially using a single receiver front-end and oscilloscope. We experimentally demonstrate characterization of signals at symbol rates up to 288 GBaud beyond the receiver bandwidth limit.

eess.SP↗

133-Tbps 1040-km (13$\times$80 km) Lumped-Amplified Transmission Over 22 THz in S-to-U-Band Using Hybrid Multiband Repeater with PPLN-Based Optical Parametric Amplifiers and EDFAs

We demonstrated 22.05-THz four-band long-haul transmission with a S-to-U-band lumped repeater consisting of PPLN-based optical parametric amplifiers and EDFAs over an 80-km-span SMF link. The achieved net bitrate was 133.06 Tbps at 1040 km with the 25.5-dBm fibre launch power designed by accounting for ISRS.

physics.optics↗

Packing Fraction of a Two-dimensional Eden Model with Random-Sized Particles

We have performed a numerical simulation of a two-dimensional Eden model with random-size particles. In the present model, the particle radii are generated from a Gaussian distribution with mean $μ$ and standard deviation $σ$. First, we have examined the bulk packing fraction for the Eden cluster and investigated the effects of the standard deviation and the total number of particles $N_{\mathrm{T}}$. We show that the bulk packing fraction depends on the number of particles and the standard deviation. In particular, for the dependence on the standard deviation, we have determined the asymptotic value of the bulk packing fraction in the limit of the dimensionless standard deviation. This value is larger than the packing fraction obtained in a previous study of the Eden model with uniform-size particles. Secondly, we have investigated the packing fraction of the entire Eden cluster including the effect of the interface fluctuation. We find that the entire packing fraction depends on the number of particles while it is independent of the standard deviation, in contrast to the bulk packing fraction. In a similar way to the bulk packing fraction, we have obtained the asymptotic value of the entire packing fraction in the limit $N_{\mathrm{T}} \to \infty$. The obtained value of the entire packing fraction is smaller than that of the bulk value. This fact suggests that the interface fluctuation of the Eden cluster influences the packing fraction.

cond-mat.stat-mech↗