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We present the design, fabrication, and characterization of mode-selective photonic lanterns using double-clad fibers. Here, we exploited several custom-pulled double-clad fibers to achieve the symmetry break required to excite higher-order…

Many experiments in biological and medical sciences currently use multiphoton microscopy as a core imaging technique. To date, solid-state lasers are most commonly used as excitation beam sources. However, the most demanding applications…

We report a phenomenon of self-sweeping in a bi-directional ring thulium-doped fiber laser, for the first time. The laser is spontaneously sweeping in both directions at a rate up to 0.2 nm/s with 15 nm sweeping range in 1.95 {\mu}m…

Optics · Physics 2018-12-10 Hongbo Jiang , Zihao Zhao , Pengtao Yuan , Lei Jin , Sze Yun Set , Shinji Yamashita

We present a novel design that exploits the focusing properties of scattering media to increase the resolution and the working distance of multimode fiber based imaging devices. Placing a highly scattering medium in front of the distal tip…

Multi-filamentation opens new degrees of freedom for manipulating electromagnetic waves in air. However, without control, multiple filament interactions, including attraction, repulsion or fusion often result in formation of complex…

Nonlinear propagation of signals in single-mode fiber is well understood, and is typically observed by measuring the temporal profile or optical spectrum of an emerging signal. In multimode fibers, the nonlinearity has both a spatial and a…

Optics · Physics 2020-08-20 Sai Kanth Dacha , Thomas E. Murphy

Laser beam profilometry is an important scientific task with well-established solutions for beams propagating in air. It has, however, remained an open challenge to measure beam profiles of high-power lasers in ultra-high vacuum and in…

Instrumentation and Detectors · Physics 2020-04-08 Christian Brand , Ksenija Simonović , Filip Kiałka , Stephan Troyer , Philipp Geyer , Markus Arndt

Multimode fibres offer the advantages of high resolution and miniaturization over single mode fibers in the field of optical imaging. However, multimode fibre's imaging is susceptible to perturbations of MMF that can lead to secondary…

In practical applications to free-space quantum communications, the utilization of active beam coupling and stabilization techniques offers notable advantages, particularly when dealing with limited detecting areas or coupling into…

Quantum Physics · Physics 2023-11-07 Dohoon Lim , Dongkyu Kim , Kyungdeuk Park , Dong-Gil Im , Yong Sup Ihn

The performance of deep learning-based multi-channel speech enhancement methods often deteriorates when the geometric parameters of the microphone array change. Traditional approaches to mitigate this issue typically involve training on…

Audio and Speech Processing · Electrical Eng. & Systems 2025-04-03 Tianqin Zheng , Jilu Jin , Hanchen Pei , Gongping Huang , Jingdong Chen , Jacob Benesty

Multimode fibers recently emerged as compact minimally-invasive probes for high-resolution deep-tissue imaging. However, the commonly used silica fibers have a relatively low numerical aperture (NA) limiting the spatial resolution of a…

Optics · Physics 2024-07-09 Zhouping Lyu , Lyubov Amitonova

This work demonstrates a broadband tunable narrow-linewidth laser based on scattering-enhanced fiber, covering the E-S-C-L wavelength bands from 1337.47 nm to 1631.39 nm, with a total tuning span of 293.92 nm. The laser employs two…

Adaptive optics methods have long been used to perform complex light shaping at the output of a multimode fiber (MMF), with the specific aim of controlling the emitted beam in the near-field. Gaining control of other emission properties,…

Broad area laser diodes are attractive for the high optical power they can produce. Unfortunately, this high power normally comes at the cost of severely reduced spatial coherence since the wide area of the semiconductor wave-guide is…

We demonstrate a wavelength spacing tunable, multiwavelength Q-switched mode-locked fiber laser (QML) based on a fiber taper deposited with graphene oxide. The operation of the laser can be understood in terms of the formation of bunches of…

Optics · Physics 2014-09-29 Lei Gao , Tao Zhu

A detailed investigation of the nonlinear multimodal interference in a short graded-index multimode optical fiber is presented. The analysis is performed for a specific device geometry, where the light is coupled in and out of the multimode…

Optics · Physics 2013-07-17 Elham Nazemosadat , Arash Mafi

Nonlinear pulse propagation in multimode fibers (MMFs) has attracted significant attention recently due to the rich spatiotemporal nonlinearities and promising applications. In practical scenarios, random birefringence in MMFs cannot be…

Optics · Physics 2025-05-15 Chaoyang Geng , Hengyu Liu , Lixia Xi , Xiaoguang Zhang , Xiaosheng Xiao

The beam quality factor M^2 for the fundamental LP01 mode of a step-index fiber is calculated in the presence of gain, in a closed form, as a function of the complex generalized V-number. It is shown that the M^2 value of a single-mode…

Optics · Physics 2015-06-05 Krishna Mohan Gundu , Parisa Gandomkar Yarandi , Arash Mafi

Beam self-imaging in nonlinear graded-index multimode optical fibers is of interest for many applications, such as implementing a fast saturable absorber mechanism in fiber lasers via multimode interference. We obtain an exact solution for…

Broad beam beamforming (BF) design in multiple-input multiple-output (MIMO) can be convenient for initial access, synchronization, and sensing capabilities in cellular networks by avoiding overheads of sweeping methods while making…

Signal Processing · Electrical Eng. & Systems 2025-08-05 Ahmet Kaplan , Diana P. M. Osorio , Erik G. Larsson