We will give an overview of our recent work on fibre-optic hvo-photon fluorescence endoscopy devices. The main component of these devices is a singlefibre coupler which acts as a low passfilter. The first device involves a lem-basedprobe head and the second includes a prism-basedprobe head. It has been well-known that two-photon fluorescence imaging systems offer distinct advantages over conven...

A highly sensitive refractive index sensor with low detection limit based on an asymmetric optical microfiber coupler is proposed. It is composed of a silica optical microfiber and an As₂Se₃ optical microfiber. Due to the asymmetry of the microfiber materials, a single-notch transmission spectrum is demonstrated by the large refractive index difference between the two optical microfibers. Compa...

The design and experimental results of a wide-band monolithic reflection-type phase shifter are presented in this paper. The phase shifter fabricated on Ba0 6Sr0 4TiO3 (BST)/sapphire consists of a coplanar waveguide (CPW) Lange coupler, a series resonated LC termination, and a bias network. The CPW Lange coupler results in a power split of 3.5 dB 0.5 dB in the range of 1.6–3.2 GHz. The BST inte...

Specific to a problem of large vibro-impact aris ing from the cutting unit of the hard rock tunnel boring machine (TBM), a hybrid magnetic coupler based on soft start was proposed in this paper. The mathematical model for total eddy current losses of such a coupler was established by field-circuit method. Then, magnetic-thermal coupling simulation was performed by virtue of three-dimensional fi...

Introduction: Multimode interference (MMI) couplers have been widely used in integrated photonic devices because of their compact size, wide optical bandwidth, polarisation independence and relaxed fabrication tolerances [1]. In most applications they operate as passive components, and only recently has their use as active components for the development of photonic switches been investigated [2...

We study two-component surface solitons in a pair of linearly coupled truncated waveguiding arrays with the Kerr nonlinearity. Symmetric solitons have a very small stability area, while those that are antisymmetric and asymmetric are stable in vast regions. Below a critical value of the coupling constant, branches of the symmetric and asymmetric modes separate, and accordingly, asymmetric solit...

Introduction Conclusions References

We study light-beam propagation in a nonlinear coupler with an asymmetric double-channel waveguide and derive various analytical forms of optical modes. The results show that the symmetry-preserving modes in a symmetric double-channel waveguide are deformed due to the asymmetry of the two-channel waveguide, yet such a coupler supports the symmetry-breaking modes. The dispersion relations reveal...