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The importance of Carbon dioxide (CO₂) gas detection as a greenhouse and exhale breathe gas is an undeniable issue. This study aims to propose a new miniaturized, low cost and portable no dispersive infrared (NDIR) system for detecting CO₂ gas.

Poly(methyl methacrylate) (PMMA)-based channels with Au coating because of its high reflection properties in IR region were used in this work. The optical windows were fabricated using PDMS polymer which is cost effective and novel in comparison to other conventional methods. The effects of channel dimensions, lengths and entrance angle of light on optical path length and losses were analyzed with four types of channel using both simulation and experimental tests.

The simulation results indicate that the 0 degree light entrance angle is the most efficient angle among different investigated conditions. The experimental data are in agreement with the simulation results regarding the loss and optical path length in different types of channel. The experimental tests were performed for the 0.5% up to 20% of CO₂ concentration under constant temperature and humidity condition. The results show that the device with 5  and 2 cm channels length were saturated in 4% and 8% concentration of CO₂ gas, respectively. Response and recovery times were depending on gas concentration and channels specifications that in average found to be 10 S and 14 S, respectively, for the largest size channel. Moreover, the environment humidity effect on detection system performance was investigated which had no considerable influence. Also, the saturation fraction absorbance value for devices with various dimensions were 0.62 and 0.8, respectively.

According to the performed curve fitting for practical situation and selected CO₂ concentration range for experimental tests, the device is useful for medical and environmental applications.

PMMA with Au deposition layer was used as a basic material for this NDIR system. Besides, a novel PDMS optical window helps to have a low cost device. The effects of channel dimensions, lengths and entrance angle of light on optical path length and losses were analyzed using both simulation and experimental tests. Using narrowband optical filter (100 nm bandwidth) helps to have a system with good CO₂ selectivity. In addition, experimental tests with different channel dimensions and lengths covered a considerable range of CO₂ concentration useful for medical and environmental applications. Finally, curve fitting was adopted for a modified Beer–Lambert law as a practical situation.

The purpose of this paper is to provide a detailed review of radiation dosimetry techniques based on optical fibre dosimeters. It presents a comprehensive bibliography of the current research activities in the area.

A range of published work on optical fibre radiation dosimeters are presented, with the merits and limitations discussed. Each radiation dosimetry technique is discussed in turn, providing examples of dosimeters using such techniques reviewed. The main focus is on gamma radiation although other radiation dosimeters are considered.

This paper provides information on the wide range of research activity into radiation dosimeters. The dose ranges of these dosimeters are presented, along with the advantages and disadvantages of different dosimetry techniques.

A comprehensive review of published research in the area of solid radiation dosimetry is presented in this paper. It provides an individual with a review of the various techniques used and most recent research in that field.

The purpose of this paper is to study fabrication of optical‐PCBs on panel scale boards in a conventional modern PCB process environment. It evaluates impacts on board design and manufacturing with the developed optical board verifiers outlining challenges and requirements for manufacturing low‐loss waveguide structures and optical building blocks. The study aims to expand the current knowledge in the field by adding results obtained by utilizing industrial production infrastructure and developed scalable manufacturing processes to fabricate optical‐PCBs and board assemblies in high‐volumes and low‐cost manner.

Impacts on board design and manufacturing were studied with the developed optical technology verifiers. One verifier is optical‐PCB with embedded waveguides, integrated i/o couplers and optical vias. Another verifier is large size PCB with optical layer. A system‐level optical board assembly with 12.5 Gb/s Tx/Rx devices on surface mounted ball grid array (BGA) modules is designed for optical link analysis. Fabricated optical structures on verifiers are evaluated of their physical characteristics utilizing optical, SEM, LSCM analysis methods. Performance testing is conducted using standard optical transmission measurement methods and equipment.

The paper provides empirical results about fabrication of multimode optical waveguides with conventional PCB process equipment. Results suggest that current coating and imaging equipments are capable of producing optical waveguide patterns with high resolution and size accuracy. However, fabricators would require larger process window and defect tolerance for processing optical materials to obtain low‐loss waveguides with sufficient yields.

Because of the limited amount of design variants in production verifiers evaluated in this paper, some impacts like effect of base material, board construction, optical layer location and beam coupling solution were not evaluated. Likewise, impacts on long‐term stability and cost were not addressed. These factors however require further investigation to address technical feasibility of optical PCBs technology prior commercial high volume production.

The paper includes implications for the development of a fabrication methods and testing procedures for optical polymer waveguide layers on PCBs.

This paper fulfils need to provide results on design, fabrication and characterization of optical PCBs and backplanes from industrial fabricator's perspective. The paper provides input for end‐user and developers to evaluate technical performance, robustness, and maturity of building blocks and supply chain to support polymer waveguide based technology for intra‐system optical links.

The purpose of this paper is to evaluate the detection performance of infrared photoelectric detection system and establish stable tracking platform.

This paper puts forward making use of the finite element analysis method to set up the infrared radiation characteristics calculation model of flying target in infrared photoelectric detection system; researches the target optical characteristics based on the target imaging detection theory; sets up the heat balance equation of target’s surface node and gives the calculation method of total radiation intensity of flying target; and deduces the target detection distance calculation function; studies the changed regulation of radiation energy that charge coupled device (CCD) gain comes from target surface infrared heat radiations under different sky background luminance and different target flight attitude.

Through calculation and experiment analysis, the results show that when the target’s surface area increases or the target flight velocity is higher, the radiation energy that CCD obtained is higher, which is advantageous to the target stable detection in infrared photoelectric detection system.

This paper uses the finite element analysis method to set up the infrared radiation characteristics calculation model of flying target and give the calculation and experiment results; those results can provide some data and improve the design method of infrared photoelectric detection system, and it is of value.

The purpose of this paper is to propose a novel method of coaxial optical precision alignment based on surface roughness and reflectiveness matching.

The micro-assembly experiment system set-up was constructed according to the principle of the coaxial optical alignment. The coaxial optical alignment error is theoretically analyzed and calculated. When the prism orthogonal alignment mechanism produces the error of 0.001°, the theoretical deviation was less than 0.87 μm and the actual experimental micro-assembly platform assembly accuracy exceeded 3 μm. A peg-in-hole precise assembly of punching pin micro-assembly experiment was done in order to validate feasibility of this method.

The results indicate that coaxial optical precision alignment could be used for the assembly of complex micro-heterogeneous system which is integrated by similar devices, such as 3D complex micro-structures, silicon micro-electro-mechanical system (MEMS) devices and non-silicon MEMS devices with flat structure.

The paper provides certain methodological guidelines for MEMS for high precision automatic assembly of complex 3D micro-structures.

Flow measurement plays an important role in modern industrial production. Flow measurement methods based on optical fiber systems have become a main research focus.

Applying flow measurement theory and the structural characteristics of optical fiber, flow measurement of paste can be achieved through a combined laser Doppler and optical fiber sensing system based on the principle of optical fiber grating sensors and flow sensors. The system is developed to include light selection, photoelectric detection, a voltage amplifier circuit and a signal filtering circuit.

The system is shown, through a comparative experiment, to be of higher accuracy than the traditional ultrasonic method.

A new method for measuring the paste flow is presented, which is based on the principle of optical fiber Doppler. The method has the advantages of convenient installation, high accuracy and low cost. Experiments show that the method is feasible.

Fundamental engineering limits to very high speed electronics switching systems are employed. These limitations are caused by packaging and interconnection constraints, as well as device switching speed. From the device viewpoint, reactive parasitics caused by the packaging/interconnection scenario are discussed. From the systems level perspective, overall delay, delay variance and power consumption are explored. The important problem of clock distribution in high speed synchronous digital systems is discussed. These limitations are then revisited with photonics implementation in mind. Comparisons are made between the electrical and photonic approaches. Some engineering limits to the photonic alternative are laid out.

This paper aims to focus on the development of an optical concentration sensor designed for measuring the concentration of components in solutions.

The operating principle of the developed sensor is based on the Bouguer–Lambert–Beer law. An optical measuring system using fiber optical cables was used for the practical implementation of the concentration sensor.

As a result of fiber optical cable use in the concentration sensor, the remote measurement principle was implemented, ensuring the instrument’s reliability and the reduction of operating costs.

The advantage of the proposed measuring system is that the sensitive element is maintenance-free, does not require power supply and can operate under severe industrial conditions. Using a fiber optic cable to transmit a light signal allows placing the sensitive element at a distance of several tens of meters from the electronics unit (the smart part).

The purpose of this paper is to view the flow concentration of the flowing material in a pipeline conveyor.

Optical tomography provides a method to view the cross sectional image of flowing materials in a pipeline conveyor. Important flow information such as flow concentration profile, flow velocity and mass flow rate can be obtained without the need to invade the process vessel. The utilization of powerful computer together with expensive data acquisition system (DAQ) as the processing device in optical tomography systems has always been a norm. However, the advancements in silicon fabrication technology nowadays allow the fabrication of powerful digital signal processors (DSP) at reasonable cost. This allows the technology to be applied in optical tomography system to reduce or even eliminate the need of personal computer and the DAQ. The DSP system was customized to control the data acquisition of 16 × 16 optical sensors (arranged in orthogonal projection) and 23 × 23 optical sensors (arranged in rectilinear projections). The data collected were used to reconstruct the cross sectional image of flowing materials inside the pipeline. In the developed system, the accuracy of the image reconstruction was increased by 12.5 per cent by using new hybrid image reconstruction algorithm.

The results proved that the data acquisition and image reconstruction algorithm is capable of acquiring accurate data to reconstruct cross sectional images with only little error compared to the expected measurements.

The DSP system was customized to control the data acquisition of 16 × 16 optical sensors (arranged in orthogonal projection) and 23 × 23 optical sensors (arranged in rectilinear projections).

Optical fibre sensors are finding wide applications in biotechnology and medicine, as a European specialist explains.