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Generation and use of orbital angular momentum (OAM) of light is finding more and more interest in a wide variety of fields of photonics: communications, optical trapping, quantum optics, and many more [1]. In the investigation of such behavior, twisting of photonic crystal fibers shows interesting physical phenomena [2]. We previously reported the ability to create helical hollow fibers by mechanically...
Multi-plane light conversion (MPLC) [1], [2] consists of a series of phase masks separated by a Fourier transform or free-space propagation and is illustrated conceptually in Fig. 1(a). Through this cascaded sequence of phase masks, and the diffraction which occurs between the masks, it is possible to implement arbitrary unitary spatial transformations. That is, any spatial input basis can be converted...
The I-SOC (Space Optical Clock on ISS) mission [1] is an ESA mission whose main goal is testing the Einstein Equivalence Principle and performing relativistic geodesy from space. It will be based on a strontium lattice clock on the ISS, which will be compared with ground clocks using advanced frequency link technologies, optical and microwave. The space clock will have 1×10−17 fractional inaccuracy,...
Distributed Raman amplification is an attractive way to improve the OSNR in optical transmission systems. However, this requires profound system knowledge to profit from these potential benefits. Especially in the case of co-directional pumped Raman amplifiers the evolution of the signal powers over the propagation distance is of interest in order to avoid signal distortions. Within the design process...
Homogeneous single-mode multi-core fibers (MCF) offer the potential for a dramatic increase of the per-fiber capacity in long-haul optical communication systems [1, 2]. Inter-core crosstalk, resulting from unwanted core coupling can limit the achievable data rates and transmission distance [3]. It has been found that short-term average crosstalk (STAX) may vary randomly over time and frequency by...
While further increasing the capacity of the SSMF is bounded by the nonlinear Shannon Limit, the annual traffic growth already exceeds the growth of the transmission capacity. In the nearest years, new traffic demands can only be accommodated by lighting a new fiber leading to a linear increase of the cost per bit. The development of communication systems based on multi-mode fibers is considered as...
Optical fibers consisted of multiple cores (multi-core fibers, MCFs) are widely regarded as the leading solution path to the optical communications capacity crunch. MCFs are also used in high power lasers, microwave photonics, and shape-sensing applications. The most common paradigm for the design and employment of MCFs is to try and restrict the direct coupling of power among different cores through...
Active modulation of light with large optical bandwidths (∼100 nm [1]) is required in photonic devices, such as modulators for fiber communications [1] and saturable absorbers for ultrafast pulse generation [2,3]. Present modulators use expensive materials, (e.g. LiNbO3 [4], III-V semiconductors [5], and Ge on silicon-on-insulator (SOI) [6]), and are limited by narrowband operation (∼20 nm for quantum-confined...
The generation of ultrashort wavepackets with optical angular momentum (OAM) enables to combine the extreme intensity, temporal localization and spectral bandwidth of pulsed light fields with topological charges. Because of additional rotational degrees of freedom, such potential applications in optical communication, optical tweezing, microscopy, or material modification, pulses with are currently...
Optical fibers technology has experienced a tremendous growth and advancement over the past several decades, not only in transmission systems for communications (where nowadays totally dominate especially at the high performances level) but also in the sensing field. For this reason, there is an ever increasing need to add new functionalities and improve the performances, through the integration on...
Bismuth (Bi)-doped fiber (BDF) lasers and amplifiers have been demonstrated in different glass hosts (i.e., aluminosilicate, phosphosilicate and germanosilicate) covering the 1150–1800nm wavelength region [1-3]. Pulsed Bi-doped fiber lasers (BDFLs) are of great interest owing to their potential applications in medicine, material processing and optical fiber communications. The first Bi-doped pulsed...
Multi-core optical fibers (MCF) are utilized for a great variety of applications in various areas of photonics, they have attracted a lot of attention in the fields of high capacity optical communications and fiber lasers. Recently we have demonstrated that nonlinear effects in MCFs, which are generally undesirable in many applications, can be utilized for nonlinear pulse combining and compression...
Fiber-optical microscopy probe have been applied in in-vivo fluorescent imaging with sub-micrometer resolution for scientific and diagnostic applications [1]. However, conventional fiber-optical magnetic microscopy probe is not well suited for imaging living biological subjects. One of the reasons is that the miniaturization of fiber-optical magnetic microscopy probe is limited by the size of micro-lens...
It is well known that degradation of an information signal during its propagation along the optical fiber communication link affects the achievable bit rate. In practice, any real transmission link introduces signal distortions that can be either recoverable (e.g., dispersive broadening) or not fully removable (e.g., noise). The sources of such unremovable distortions leading to loss of information...
Nonlinear Fourier transform (NFT) can be used as a tool to overcome nonlinearity in optical fibre communication systems [1-5]. Signalling on the continuous spectrum (CS), defined by NFT, can be performed as well as on solitons. The feasibility of this technique is demonstrated by simulation and experiment [2-5]. Amplified spontaneous emission (ASE) noise is considered as the main perturbation that...
Wavelength tuneable lasers for 40G and 100G coherent optical communications systems need to meet stringent requirements on narrow linewidth emission across the entire tuning range, with typical values of 300–500 kHz required in commercial systems. Higher capacities can be achieved in next generation systems by employing higher order modulation formats such as 16QAM or 64QAM. However, such systems...
Orbital angular momentum (OAM) of light provides an additional degree of freedom for multiplexing the data streams in optical communications, increasing further the channel capacity [1]. Applications of OAM for both classical data transmission [2] and quantum information [3] have been demonstrated. The key step towards robust, suitable for massive production, and cost-efficient OAM-assisted communications...
Optical domain walls (DW) correspond to a localized structure of the kink type that connects two regions of space with different polarizations [1]. In such a symbiotic system, the fast polarization knots lead to two anticorrelated coupled twin-waves for which the strong binding force imposed by cross-phase modulation (XPM) can compensate for the classical defocusing regime. In this contribution, we...
Due to the so-called capacity crunch, an increasing number of research have been focused on the subject of efficient signalling on nonlinear optical fibres and particularly methods based on nonlinear Fourier transform (NFT) [1-6]. This field of research includes the design of optical transmission using discrete spectrum, continuous spectrum (CS) [1], and combination of all degrees of freedom [2]....
Fiber lasers operating at 2μm wavelength range have great potential in applications like coherent LIDAR [1] and remote sensing [2]. In particular, the 2.09∼2.1μm range exhibits low atmosphere attenuation [1]. The 2μm region could also be a new window for optical communication in hollow core fibers [3], where narrow linewidth and linearly polarized light is preferred. Efficient 2μm range lasing has...
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