Automated Laser System Research Articles

Wide-range and area-selective threshold voltage tunability in ultrathin indium oxide transistors

The scaling of transistors with thinner channel thicknesses has led to a surge in research on two-dimensional (2D) and quasi-2D semiconductors. However, modulating the threshold voltage (VT) in ultrathin transistors is challenging, as traditional doping methods are not readily applicable. In this work, we introduce a optical-thermal method, combining ultraviolet (UV) illumination and oxygen annealing, to achieve broad-range VT tunability in ultrathin In2O3. This method can achieve both positive and negative VT tuning and is reversible. The modulation of sheet carrier density, which corresponds to VT shift, is comparable to that obtained using other doping and capacitive charging techniques in other ultrathin transistors, including 2D semiconductors. With the controllability of VT, we successfully demonstrate the realization of depletion-load inverter and multi-state logic devices, as well as wafer-scale VT modulation via an automated laser system, showcasing its potential for low-power circuit design and non-von Neumann computing applications.

Robust and rapidly tunable light source for SRS/CARS microscopy with low-intensity noise

We present a fully automated laser system with low-intensity noise for coherent Raman scattering microscopy. The robust two-color system is pumped by a solid-state oscillator, which provides Stokes pulses fixed at 1043 nm. The tunable pump pulses of 750 to 950 nm are generated by a frequency-doubled fiber-feedback femtosecond optical parametric oscillator. The resulting pulse duration of 1.2 ps provides a viable compromise between optimal coherent Raman scattering signal and the necessary spectral resolution. Thus a spectral range of 1015 to 3695 cm − 1 with spectral resolution of

Kinect4FOG: monitoring and improving mobility in people with Parkinson’s using a novel system incorporating the Microsoft Kinect v2

Parkinson’s is a neurodegenerative condition associated with several motor symptoms including tremors and slowness of movement. Freezing of gait (FOG); the sensation of one’s feet being “glued” to the floor, is one of the most debilitating symptoms associated with advanced Parkinson’s. FOG not only contributes to falls and related injuries, but also compromises quality of life as people often avoid engaging in functional daily activities both inside and outside the home. In the current study, we describe a novel system designed to detect FOG and falling in people with Parkinson’s (PwP) as well as monitoring and improving their mobility using laser-based visual cues cast by an automated laser system. The system utilizes a RGB-D sensor based on Microsoft Kinect v2 and a laser casting system consisting of two servo motors and an Arduino microcontroller. This system was evaluated by 15 PwP with FOG. Here, we present details of the system along with a summary of feedback provided by PwP. Despite limitations regarding its outdoor use, feedback was very positive in terms of domestic usability and convenience, where 12/15 PwP showed interest in installing and using the system at their homes.Implications for RehabilitationProviding an automatic and remotely manageable monitoring system for PwP gait analysis and fall detection.Providing an automatic, unobtrusive and dynamic visual cue system for PwP based on laser line projection.Gathering feedback from PwP about the practical usage of the implemented system through focus group events.

Scattering of a laser beam on a wet blood smear and measurement of red cell size distribution

We report an automated laser system that allows the red cell size distribution to be measured. Experiments are performed on laser light scattering by a suspension of oriented red blood cells (a wet blood smear). Based on an analysis of the angular distribution of light intensity in the diffraction pattern, we have restored the red cell size distribution. The average diameter of a red blood cell is determined with an error of less than 1 %, and the spread of red blood cells in size – with an error of about 20 %. We discuss the problems of photometry and processing of diffraction patterns, preparing blood samples and data processing algorithms, including methods for solving the inverse scattering problem.

Utilization of a digital-versatile-disc pickup head for benchtop laser microfabrication

Laser microfabrication is now offering interesting solutions to rapidly produce high-resolution photomasks or microstructures. However, most works require expensive commercial lasers and computer numerical control platforms, limiting its use by a large public. In this paper, we report the construction of a simple, custom-made, easily reproducible, automated laser system, based on a DVD optical pickup head. A user-friendly computer interface specifically designed to operate a motorized three-axis platform with micrometric precision controls focus distance and in-plane displacements. Writing performance characterization for both direct ablation and sintering of commercial black toner demonstrated flexibility in tridimensional microfabrication resolution and speed thanks to precise management of laser power and exposure time, with a minimal resolution of 3.1 μm.

Specific features of laser cutting of steel sheets and monitoring of sample quality after laser influence

An automated laser system with an 8-kW quantum generator with the beam quality not worse than that of a single-mode laser is described. The possibility of using such a system in procurement production for cutting carbon and stainless steel sheets is demonstrated. The quality control of the blank material shows that the properties of the latter satisfy appropriate standards.

Industrial Nd:YAG laser with a three-mirror cavity and its applications

An investigation was made of the generation of separate trains of radiation pulses in an Nd:YAG laser with two optically coupled cavities. The trains consisted of equidistant pulses. Each pulse was of 130 ns duration, governed by the initial transmission of a passive laser switch based on an LiF:F2- crystal. A power supply unit with mixed pumping was used to control the energy and temporal parameters of the pulse trains. Industrial applications of an automated laser system with a combined radiation source based on a CO2 laser and a passively Q-switched Nd:YAG laser were demonstrated.

Automated laser system for remote measuring of the sea water fluorescence

A short description of the fluorescent shipboard lidar based on a solid-state laser and two PRAVETS-8 personal computers is presented. Results of field observations are reported.

An automated laser system for eye surgery

The use of lasers in ophthalmology is discussed, and the procedure and requirements of ophthalmic laser surgery are described. An overview of a proposed laser system for eye surgery is given, and its operation is described. Progress and research to date are reviewed.

Classical chaos and quantum simplicity: Highly excited vibrational states of HCN

Direct overtone spectra of H 12C 14N, H 13C 14N, and H 12C 15N have been measured between 15 000 and 18 500 cm−1 with a precision of 0.001 cm−1. These were obtained using intracavity photoacoustic spectroscopy, with a fully automated laser system. The spectra are unperturbed. The transition energies and rotational constants are in good agreement with predictions of first order anharmonic constants. Classical trajectories for HCN have been computed on the best experimentally parameterized potential, and found to be stochastic 12 990 cm−1 above the ground state. Quantal density of states were computed for HCN and show that if extensive vibrational coupling occurs, the observed states would be highly perturbed. The simplicity of the observed states is shown to be expected given a Franck–Condon type limitation on significantly perturbing states. The results show the inapplicability of classical dynamics for predicting the dynamics of molecular vibrations.