M. Yasin

Estimation of metal surface roughness using fiber optic displacement sensor

A fiber optic displacement sensor is proposed to estimate the roughness of metal surface using the intensity modulation technique. A light beam is launched onto the metal surface via a bundled fiber. The reflected light from the surface is collected and then routed to a silicon detector. The level of roughness for aluminum, stainless steel and copper samples are estimated to be approximately 27, 26, and 20% respectively by fixing the object within the linear range of the sensor. The output voltages are measured as a function of lateral distance to estimate the roughness of the surface.

Simple design of optical fiber displacement sensor using a multimode fiber coupler

A simple design sensor is demonstrated using a fabricated multimode plastic fiber coupler in conjunction with reflective intensity modulation technique. The performances of this sensor are investigated for different light sources. This sensor uses only one fiber for sending and receiving the light and therefore only the back slope exists. The sensor shows the highest performance with the use of yellow light source, which has the highest intensity and the smallest beam divergence. The sensitivity, linear range, resolution and dynamic range of the sensor are obtained at 0.0001 mV/μm, 1500 μm, 70 μm, and 5.0 mm, respectively. The simplicity of the design, high degree of sensitivity, dynamic range and the low cost of the fabrication make it suitable for real field applications.

Design and operation of a concentric-fiber displacement sensor

Abstract A concentric-fiber displacement sensor is demonstrated using a developed theory to support the experimental findings. The theoretical analysis uses an electromagnetic Gaussian beam approach to determine the transfer function of the sensor. The sensor has two operating ranges with a good linearity; namely, the front slope and back slope. On the front slope, the sensitivities are obtained at 3.6 and 2.1 mW/μm for the theoretical and experimental approaches, respectively; while on the back slope the sensitivities are 1.6 and 0.52 mW/μm for theoretical and experimental approaches, respectively. This sensor has many potential applications such as automated monitoring control, position control, and micro-displacement sensing in the hazardous regions.

Effect of tilting angles on the performance of reflective and transmitting types of fiber optic-based displacement sensors

The performances of the fiber optic-based displacement sensor with reflective and transmitting techniques were investigated. The effects of axial displacement on the detected voltage were investigated for different tilting angles of the reflective and receiving fibers. Three types of light sources were used, yellow and red He-Ne including a green pointer laser at peak wavelengths of 594, 633, and 533 nm correspondingly. The highest sensitivity and resolution were obtained at 0.0017 mV/μm and 4 μm, respectively with the employment of a 594 nm laser as the light source. These were attributed to the output power and beam quality of the laser which was the highest. The tilting angles didn’t change the sensitivity and resolution of the sensors in both setups. The widest linear range was obtained at 2410 μm with the transmitting technique. The simplicity of the design, high degree of sensitivity, linear range, non-contact measurement and low cost fabrication make it suitable for industrially-orientated applications that include control and micro-displacement in the hazardous region.

Optical non-contact micrometer thickness measurement system for silica thick films

In this paper, a novel optical approach is proposed and demonstrated for the non-contact measurement for the thickness of silica thick films. This approach is based on the principal of an optical based displacement sensor. The calibration curve for the measurement of the thickness of an unknown sample is obtained using four sample with known thicknesses of 6.90, 10.23, 19.69 and 25.47 μm respectively. As compared to a prism coupler, which is assumed to provide the most precise measurement of thick film thicknesses, the proposed system has an error of approximately 8%. The proposed method is able to provide a simple, low cost and time saving approach in measuring thick films thicknesses during fabrication.

PERFORMANCE ANALYSIS OF COPPER TIN SULFIDE, Cu2SnS3 (CTS) WITH VARIOUS BUFFER LAYERS BY USING SCAPS IN SOLAR CELLS

This work examines the performance of the Cu2SnS3 (CTS) solar cells using the solar cell capacitance simulator (SCAPS) approach. The performance of the CTS solar cell was evaluated in terms of Voc, Jsc, fill factor and efficiency. The structural parameter variation of CTS solar cell has been studied in terms of buffer and absorber layer thickness, bandgap, effect of temperature on total efficiency of the solar cell. Increasing the thickness of the CdS buffer layer decreases the efficiency of the simulated solar cell. A significant increase in the efficiency of the solar cell to 20.36% was obtained with a simulated buffer layer thickness to 10nm. In terms of the CTS absorber layer thickness, the efficiency of the solar cell increases by increasing the thickness of absorber layer. By setting the thickness of CTS to 4.0μm, the efficiency obtained is 20.36%. It is observed that an increase in the bandgap can enhance the efficiency of the solar cell. In the performed simulation, an 0.9eV bandgap resulted in a 11.58% cell efficiency and a 1.25eV bandgap resulted in 21.96% cell efficiency. In terms of temperature, the efficiency of 20.36% was obtained at 300K, and as the temperature increases, cell efficiency will decrease.