Black phosphorus film as Q-switcher in neodymium-doped fiber laser.

We present the successful development of a 1089.4 nm Q-switched laser employing a neodymium-doped fiber (NDF) as the active fiber and black phosphorus (BP) as the saturable absorber (SA). The BP SA was fabricated by inserting BP compound into a polyvinyl alcohol (PVA) host polymer, exhibiting a saturable absorption of 2.

Highly sensitive detection of low-concentration sodium chloride solutions based on a gold-coated prism in Kretschmann setup.

A gold-coated Kretschmann setup has been constructed and explored as a surface plasmon resonance (SPR) platform, specifically tailored for the detection of low-concentration sodium chloride (NaCl) solutions. The setup employs a BK7 prism coated with a 50 nm gold layer, serving as a plasmonic layer, to induce resonance. This resonance arises from the interplay between light waves and free electrons propagating at the interface of two media.

Passively harmonic dissipative soliton generation in normal dispersion erbium-doped fiber laser using SMS fiber as artificial saturable absorber.

Passively harmonic mode-locking has been experimentally demonstrated in an erbium-doped fiber laser with large normal dispersion using single-multi-single mode structure as artificial saturable absorber. By increasing the pump power under the same polarization setting, the mode-locking operation can switch from fundamental mode-locked to 5th order harmonic mode-locked. Highest repetition rate of 4.

Copper phthalocyanines as a mode-locker in an Er-doped fiber laser.

We demonstrate a mode-locked erbium-doped fiber laser (EDFL) utilizing copper phthalocyanines (CuPc) as a saturable absorber (SA) for the first time, to the best of our knowledge. The investigated SA was prepared using a simple, low-cost and straightforward technique, whereby the CuPc powder was embedded into polyvinyl alcohol (PVA) to form a thin film. The thin film acted as a mode-locker when it was incorporated into the EDFL cavity to produce output pulses at a repetition rate of 1.

Domain-wall dark pulse generation with SMF-GIMF-SMF structure as artificial saturable absorber.

We experimentally demonstrated the generation of domain-wall dark pulse in an Erbium-doped fiber laser using the combination of a 10 cm graded index multimode fiber sandwiched by single mode fibers as artificial saturable absorber. The interaction of phase difference in grade index multimode fiber allowed the stable dual-wavelength oscillation in the cavity. The dual-wavelength centered at 1567.

Sodium carbonate modulated ultrashort mode-locked stretched pulses in an erbium-doped fiber laser.

In this paper, we propose a new, to the best of our knowledge, saturable absorber (SA) based on sodium carbonate ( ) for producing an ultrafast mode-locked stretched pulse in a passively erbium-doped fiber laser at near-zero dispersion. The solid film of a -SA was fabricated by the drop-casting method using polyvinyl alcohol as a host polymer. The modulation depth of the proposed SA, which was measured by a balanced twin detector technique, was 2.

Review of Microbottle Resonators for Sensing Applications.

Microbottle resonators (MBR) are bottle-like structures fabricated by varying the radius of an optical fiber. MBRs can support whispering gallery modes (WGM) by the total internal reflection of the light coupled into the MBRs. MBRs have a significant advantage in sensing and other advanced optical applications due to their light confinement abilities in a relatively small mode volume and having high Q factors.

Single and Bunch Soliton Generation in Optical Fiber Lasers Using Bismuth Selenide Topological Insulator Saturable Absorber.

In this work, we present the generation of two distinct types of soliton pulses using a Bismuth Selenide (BiSe) saturable absorber (SA) synthesized in our laboratory. The soliton pulses were generated in two different laser cavity configurations, resulting in two types of solitons: a soliton pulse with Kelly sidebands and a bunched soliton pulse with peak-dip sidebands. Both solitons operated at the fundamental repetition rate-23.

Dissipative Soliton Mode-Locked Erbium-Doped Fiber Laser Using NbAlC Nanomaterial Saturable Absorber.

We report the fabrication of an erbium-doped fiber-based saturable absorber (SA) of niobium aluminium carbide (NbAlC) nanomaterial that can generate a dissipative soliton mode-locked pulse. Stable mode-locked pulses operating at 1530 nm with repetition rates of 1 MHz and pulse widths of 6.375 ps were produced using polyvinyl alcohol (PVA) and the Nb2AlC nanomaterial.

Mode-locked ytterbium-doped fiber laser with zinc phthalocyanine thin film saturable absorber.

A stable mode-locked laser was demonstrated using a newly developed zinc phthalocyanine (ZnPc) thin film as passive saturable absorber (SA) in ytterbium-doped fiber laser (YDFL). The ZnPc thin film was obtained using a casting method and then inserted between the two fiber ferrules of a YDFL ring cavity to generate mode-locked pulses. The resulting pulsed laser operated at a wavelength of 1034.

Skin lesion classification using multi-resolution empirical mode decomposition and local binary pattern.

Skin cancer is the most common type of cancer in many parts of the world. As skin cancers start as skin lesions, it is important to identify precancerous skin lesions early. In this paper we propose an image based skin lesion identification to classify seven different classes of skin lesions.

Nanosecond Q-switched laser with PEDOT: PSS saturable absorber.

We demonstrate deployment of the nonlinear saturable absorption property of the organic material poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT: PSS) for pulse generation in the near-infrared region. The saturable absorber (SA) film was made using a straightforward process of depositing a layer of the PEDOT: PSS material onto a polyvinyl alcohol (PVA) film. The prepared SA was inserted into an erbium-doped fiber laser cavity as a -switcher to produce laser pulses with a maximum pulse rate of 92.

Self-starting triple-wavelength vector dark soliton with a bismuth-doped fiber saturable absorber.

We report on the generation of a triple-wavelength vector dark soliton in an all-fiber ring cavity of erbium-doped fiber laser mode-locked with a bismuth-doped fiber saturable absorber. The formation of the triple-wavelength vector dark soliton is due to the cross-phase coupling derived from the cavity birefringence. The mode-locked laser operated at a 1.

Optical and Photoacoustic Properties of Laser-Ablated Silver Nanoparticles in a Carbon Dots Solution.

This study used the carbon dots solution for the laser ablation technique to fabricate silver nanoparticles. The ablation time range was from 5 min to 20 min. Analytical methods, including Fourier transform infrared spectroscopy (FTIR), UV-visible spectroscopy, transmission electron microscopy, and Raman spectroscopy were used to categorize the prepared samples.

Precursors to non-invasive clinical dengue screening: Multivariate signature analysis of in-vivo diffuse skin reflectance spectroscopy on febrile patients in Malaysia.

Dengue diagnostics have come a long way. Attempts at breaking away from lab-oriented dengue detection, such as NS1 antigen, IgM or IgG antibodies detection have extensively received numerous coverage. As a result, rapid detection tests (RDTs) have started to gain inroads in medical practice.

Nanosecond passively Q-switched fibre laser using a NiS based saturable absorber.

Q-switched pulse laser generation is successfully demonstrated in both Erbium-doped fibre laser (EDFL) and Thulium-doped fibre laser (TDFL) cavities by employing Nickel disulfide (NiS) as a saturable absorber (SA). Q-switched pulse laser operation at 1.55 μm and 2.

Nanosecond pulse laser generation at 1.55 and 2 μm regions by integrating a piece of newly developed chromium-doped fiber-based saturable absorber.

This paper demonstrated the nanosecond pulse laser operation at 1.55 and 2 μm wavelength regions using a newly develop chromium-doped fiber (CrDF) as a saturable absorber (SA) to convert efficiently continuous-wave laser operation to nanosecond pulse laser operation. The laser uses an erbium-doped fiber (EDF) and thulium-doped fiber as the gain medium.

Investigation of Surface Plasmon Resonance (SPR) in MoS- and WS-Protected Titanium Side-Polished Optical Fiber as a Humidity Sensor.

In this paper, we report the effects of a side-polished fiber (SPF) coated with titanium (Ti) films in different thicknesses, namely 5 nm, 13 nm, and 36 nm, protected by a thin layer of transition metal dichalcogenides (TMDCs) such as molybdenum disulfide (MoS) and tungsten disulfide (WS), which provide ultra-sensitive sensor-based surface plasmon resonance (SPR) covering from the visible to mid-infrared region. The SPF deposited with Ti exhibits strong evanescent field interaction with the MoS and WS, and good optical absorption, hence resulting in high-sensitivity performance. Incremental increases in the thickness of the Ti layer contribute to the enhancement of the intensity of transmission with redshift and broad spectra.

Ultrashort pulse generation with an erbium-doped fiber laser ring cavity based on a copper oxide saturable absorber.

A soliton mode-locked erbium-doped fiber (EDF) laser has been experimentally demonstrated using copper oxide (CuO) thin film as a saturable absorber (SA). The dispersion of the EDF cavity including the CuO-SA was balanced by a suitable length of single-mode fiber (SMF). The fabricated CuO-SA has 3.

Reversible thermo-pneumatic valves on centrifugal microfluidic platforms.

Centrifugal microfluidic systems utilize a conventional spindle motor to automate parallel biochemical assays on a single microfluidic disk. The integration of complex, sequential microfluidic procedures on these platforms relies on robust valving techniques that allow for the precise control and manipulation of fluid flow. The ability of valves to consistently return to their former conditions after each actuation plays a significant role in the real-time manipulation of fluidic operations.

All-fiber dual wavelength passive Q-switched fiber laser using a dispersion-decreasing taper fiber in a nonlinear loop mirror.

This paper describes a proposal and successful demonstration of a dual wavelength all-fiber passively Q-switched erbium-doped fiber ring laser. The Q-switch operation was realized by using a nonlinear loop mirror that incorporated an unbalanced dispersion-decreasing taper fiber to act as a saturable absorber without additional elements. This setup enabled a fiber ring laser to achieve a performance of 48.

Biosensing enhancement of dengue virus using microballoon mixers on centrifugal microfluidic platforms.

Dengue is the current leading cause of death among children in several Latin American and Asian countries. Due to poverty in areas where the disease is prevalent and the high cost of conventional diagnostic systems, low cost devices are needed to reduce the burden caused by dengue infection. Centrifugal microfluidic platforms are an alternative solution to reduce costs and increase the availability of a rapid diagnostic system.

Classification of reflected signals from cavitated tooth surfaces using an artificial intelligence technique incorporating a fiber optic displacement sensor.

An enhanced dental cavity diameter measurement mechanism using an intensity-modulated fiber optic displacement sensor (FODS) scanning and imaging system, fuzzy logic as well as a single-layer perceptron (SLP) neural network, is presented. The SLP network was employed for the classification of the reflected signals, which were obtained from the surfaces of teeth samples and captured using FODS. Two features were used for the classification of the reflected signals with one of them being the output of a fuzzy logic.

Gain-shift induced by dopant concentration ratio in a Thulium-Bismuth doped fiber amplifier.

This paper details the effect of Thulium and Bismuth concentration ratio on gain-shift at 1800 nm and 1400 nm band in a Thulium-Bismuth Doped Fiber Amplifier (TBDFA). The effect of Thulium and Bismuth's concentration ratio on gain shifting is experimentally established and subsequently numerically modeled. The analysis is carried out via the cross relaxation and energy transfer processes between the two dopants.

Latex micro-balloon pumping in centrifugal microfluidic platforms.

Centrifugal microfluidic platforms have emerged as point-of-care diagnostic tools. However, the unidirectional nature of the centrifugal force limits the available space for multi-step processes on a single microfluidic disc. To overcome this limitation, a passive pneumatic pumping method actuated at high rotational speeds has been previously proposed to pump liquid against the centrifugal force.