Branch of Optoelectronic Devices

Our team extensively supports the optics/optoelectronics related R&D activities of Furukawa Electric Co., Ltd., which has strong position on telecom and high-power laser market.

We have close cooperation with our Japanese partner, and work on the development of new, next-generation products or optimization of product features.

Our main fields are:

  • Electro-optical-thermal design of semiconductor laser sources
  • Optical system design for coupling optics with assembling tolerance analysis
  • Digital signal processing and control electronics development

The leading-edge technologies usually mean special problems that are not supported by commercial simulation tools. Our major skills are:

  • Numerical model building and analysis
  • Simulation software tool development & implementation
  • Manufacturing support (simulations and optics lab. experiments)

Our members have deep scientific background and we offer unique simulations in MATLAB, Python, C/C++. Numerical model building always means physics-based model development, which runs in parallel with prototype design. It results faster and cheaper development, so improved competitiveness on market.

Our simulations contributed to the design of Furukawa’s next-generation products

Ultra-micro, narrow linewidth ITLA for optical digital coherent communication

120W high-brightness fiber coupled LD module with spatial beam multiplexing

Recent publications:

R. Sefel, P. Nyakas, T. Karpati, G. Varga, and Y. Kawakita; “Reflection Spectra Analysis and Optimization of Phase-modulated Waveguide-grating Reflectors”; NUSOD Conference, PD09pd (2020)

M. Nishita, Y. Higa, N. Matsubara, J. Hasegawa, K. Yamaoka, M. Ariga, Y. Inaba, M. Kimura, M. Wakaba, M. Yoshida, K. Maruyama, S. Okuyama, T. Suzuki, H. Ishii, V. Mikhailov, R. Sefel, Y. Kawakita; “Compact Tunable DBR/Ring Laser Module Integrated with Extremely-high-D PLC Wavelength Locker”; OFC 2020, M2A.6 (2020)

R. Sefel, P. Nyakas, T. Karpati, G. Varga, and Y. Kawakita; “Implementation of Rectified Ring Resonator Model into Coupled Mode Theory through Appropriate Inner Boundary Conditions”; NUSOD Conference, MPDP1 (2019)

Yuta Ishige, Eisaku Kaji, Etsuji Katayama, Yutaka Ohki, Gábor Gajdátsy, and András Cserteg; “120W, NA_0.15 fiber coupled LD module with 125-μm clad/NA 0.22 fiber by spatial coupling method”, Proc. SPIE 10514, High-Power Diode Laser Technology XVI, 105140M (2018);

Branch of Optical Fiber Design 

Running projects:

  • Simulation of wavepropagation in optical fibers to predict waveguide properties
  • Application of the Coupled Mode Theory to determine fiber loss
  • Molecular dynamic simulation of dielectric materials
  • Applying Reverse Monte Carlo modeling to obtain realistic structures based on X-ray diffraction measurements


Fiber refractive index profile for a 3D BPM

Wavepropagation in the cross-section

Coupled mode theory for microdeformations

CMT theory describes coupling of the fundamental mode to cladding modes. The coupling is enhanced by the virtual refractive index perturbations caused by the microdeformations.

Molecular dynamic simulation

Structural analysis is used to investigate the effect of different manufacturing conditions, like temperature, pressure, cooling rate and so on. We may conclude based on this to the physical properties of the material.

Reverse Monte Carlo analysis

RMC analysis is used for glass with different dopings. RDF from X-ray diffraction is used.

Obtained structure is useful to analyse some structural properties. For example, ring statistics.


T. Mihálffy, Z. Várallyay, K. Mukasa, ” Combined Mechanical-Optical Simulation to Predict Microbending Loss of Single Mode Fibers” EOCC 2019, Fukuoka, Japan 7-11 July 2019

J. W. Nicholson, R. Ahmad, A. DeSantolo, and Z. Várallyay, JOSA B 34, A1-A7 (2017).

Z. Várallyay, et al. Furukawa Review 47, 58-62 (2016).

Z. Várallyay et al., Opt. Fib. Technol. 21, 180–186 (2015).

Á. Szabó, Z. Várallyay, A. Rosales, and C. Headley, Appl. Phys. B 0946-2171, 1-7 (2015).

Á. Szabó, Z. Várallyay, Photon. Technology Lett., 24, 122-124 (2012).

Z. Várallyay, and J. C. Jasapara, Opt. Express 17, 17242-17252 (2009).

Branch of Applied Mechanics

Our goal is to support the Furukawa Electric Group’s activities in many fields of application, using our knowledge on solid and fluid mechanics and related areas. We believe that the right combination of numerical simulation, experimental studies and theoretical considerations leads to a problem-oriented approach which has the best chance to produce answers to challenging problems.

During the past years, we have worked with many research and business units of the Furukawa Electric Group. Our main fields of analysis include:

  • solid mechanics (linear and nonlinear stress analyses, advanced mechanical and material models etc.),
  • fluid mechanics (laminar and turbulent flows, transport problems etc.),
  • heat transfer (measurement and simulation)

The list of our software packages includes commercial, open-source and, in some cases, in-house-developed codes. This provides us with a flexibility of choosing the right tool for the problem.

Illustrations of our wide range of activities

Microscopic image for material study

Streamlines in a volume

Cold forming simulation

Mechanical property measurement

Calculated and measured cooling

Recent publication:

Attila Palfalvi, Drew W. Hazelton: Analysis of winding and cooling stress of a HTS coil. HTS Modeling Workshop 2016, 15th-17th June 2016, Bologna, Italy.