Ultra-short of pico and femtosecond soliton laser pulse using microring resonator for cancer cells treatment

A system of microring resonators (MRRs) incorporating with an add/drop filter system is presented in which ultra-short single and multi temporal and spatial optical soliton pulses can be simulated and used to thermalbased killing of abnormal cells, tumor and cancer, applicable in nanomedical treatments. This proposed system uses chaotic signals generated by a bright soliton pulse within a nonlinear MRRs system. Interaction between gold nanoparticles and ultra-short femtosecond and picosecond laser pulses holds great interest in laser nanomedicine. By using the appropriate soliton input power and MRRs parameters, required spatial and temporal signals are generated spreading over the spectrum. Results obtained show that smallest single temporal and spatial soliton pulse with FWHM = 712 fs and FWHM = 17.5 pm could be generated respectively. The add/drop filter system is used to generate high capacity ultra-short soliton pulses in the range of nanometer/second and picometer/second

Nd:YAG laser welding of stainless steel 304 for photonics device packaging

Although pulsed Nd:YAG laser welding has been widely used in microelectronics and photonics packaging industry, a full understanding of various phenomena involved is still a matter of trials and speculations. In this research, an ultra compact pulsed Nd:YAG laser with wavelength of 1.064 µm has been used to produce a spot weld on stainless steel 304. The principal objective of this research is to examine the effects of laser welding parameters such as laser beam peak powers, pulse durations, incident angles, focus point positions and number of shots on the weld dimensions: penetration depth and bead width. The ratio of the penetration depth to the bead width is considered as one of the most critical parameters to determine the weld quality. It is found that the penetration depth and bead width increase when the laser beam peak power, pulse duration and number of shot increase. In contrast, the penetration depth decreases when the laser beam defocus position and incident angle increase. This is due to the reduction of the laser beam intensity causing by the widening of the laser spot size. These experimental results provide a reference on an optimal laser welding operations for a reliable photonics device packaging. The results obtained shows that stainless steel 304 is suitable to be used as a base material for photonics device packaging employing Nd:YAG laser welding technique

Optical pressure sensors using interferometric techniques

An investigation of methods of optical pressure sensors using a novel polarimetric interferometric approach are presented. The use of several techniques and their experimental arrangements are demonstrated and discussed, for which results have indicated possible applications in pressure measurement. A comparison of their sensitivities to applied force has been made, using coated and uncoated standard single mode fibre as the sensing medium, and the stability of the output to temperature variations over the range 20 °C to 95 °C also demonstrated. This scheme has been discussed as a possible element for a differential pressure flow sensor. An optical pressure sensor, using a low-coherence technique and a photoelastic material as the sensing element, is also presented. A change in the optical path of light propagating in the stressed sensing element has been observed by monitoring a corresponding change in that optical path in a "recovery" optical interferometer. Results have shown a linear relationship between this change in path difference and applied pressure. Further, the measurement of force/pressure-induced birefringence has been investigated using a photoelastic technique, and in this case, the light source employed was a "quasi-white light", short coherence light source, a light emitting diode (LED). Its output was coupled into a multimode fibre before entering the processing interferometer. With the use of the processing interferometer, the sensing element birefringence was observed when a force was applied. The sensing material properties such as elastic limit, stress-relaxation and thermal effects were also investigated and are discussed, in light of the applications of the technique. The characteristics of three individual types of polarisation maintaining fibres (Hi-Bi), for pressure sensing applications using a quasi-distributed sensing technique are presented. The output light from a low-coherence source was coupled into the fibre via one of the two polarisation modes, where the location of the coupling point was located by using a basic Michelson interferometer. The theoretical aspects of the sensor system and its experimental arrangement are discussed and demonstrated. A number of sensor applications such as a pressure/force sensor, or a position sensor, in addition to an investigation of fibre characteristics such as beat length and birefringence measurements are demonstrated. The device sensitivity to variations in temperature for these measurement is investigated

High-Q and temperature stable photonic biosensor based on grating waveguides

In this work, analytical modeling and parameter evaluation of a photonic biosensor using cascaded silicon grating waveguides is illustrated. The sensor design consists of two cascaded waveguides with symmetric sidewall gratings to broaden the stop band region of the transmission spectra. In the work, the structure is first analyzed using the transfer matrix method. The parameter values are then optimized to obtain a sharper resonant peak in the center of the stop band. Notably, the resonant band of this structure provides a high Q factor (of 1.544 × 105), which significantly improves the limits of detection. The sensor has been designed to detect the presence of biomaterial material (seen corresponding to a change in refractive index) on its surface by changing the change in device resonant wavelength. In this study, the effect of temperature on the detection of such biomaterials has also been evaluated, as has the temperature sensitivity of the device which is -0.0075nm/oC, over a temperature range of 18 oC to 34 oC

An integrated microring circuit design for optoelectronic transformer applications

The on-chip scale circuit of the optoelectronic transformer is designed and manipulated using the microring resonator system. By using the monochromatic input light source, the electro-optic signals can be generated and functioned as the step up and down conversion by mean of the on-chip optoelectronic transformer. The step up and down of the electro-optic related power conversions can be obtained via the input and drop port connections. The results obtained have shown that the flexible up and down electro-optic conversion ratios of 1: 5 and 10:1 for the step up and down conversions, respectively. The uses light source wavelength source was centered at 800 nm, where the conversion stability of 1600 fs is noted. The linearity trend of the conversion stability is confirmed

Monitoring of traffic using unmanned aerial vehicle in Malaysia landscape perspective

The theoretical investigation has been performed on the implementation of optical Mobius shape in add-drop microring resonator. The modified add-drop Mobius configuration is used to investigate the optical bistability and the spectral transmission. The optical bright soliton pulse is used as the input source of the resonator system. The pulses propagation of the resonator system is modelled using the iterative programming based on the transfer matrix analysis equations. The enhancement of nonlinear effect of the resonator system is achieved by the add-drop Mobius resonator configuration. The system has been modelled for a variation of coupling coefficient for increase the bistable signal properties. The Add-drop Mobius MRR generated a bistable signal with 6.01 mW hysteresis width, and 9.47 mW output switch power with optimized radius of 5 µm outer and 4.5 m inner ring parts with 50 mW controlled power and input power. Mobius configuration is found as the better shape of resonator cavity that capable of optical switching application

Digital Binary Codes Transmission via TDMA Networks Communication System Using Dark and Bright Optical Soliton

In this study, new system of microring resonator forquantum cryptography in network communication is proposed.optical potential well can be generated and propagate via anonlinear modified add/drop interferometer systemincorporated with a beam splitter and a time division multipleaccess (TDMA) system wherein the quantum binary codes canbe generated, propagated and transmitted. A system known asoptical multiplexer can be used to increase the channel capacityand security of the signals, where the beam splitters generatehigh capacity of binary codes within the proposed system.Therefore, ring resonator system is used to form the opticalpotential wells. The multiplexed potential wells are formed andtransmit via an available link, where the logic codes can be sentout with different time, used for high capacity transmission ofthe secured data. In this work narrow pulses with FHHM of 9.57nm and 8 nm could be obtained from the drop and throughports of the add/drop interferometer system respectively. Theoutputs of different center wavelengths are combined and usedto generate multiple potential well signals, where the multiplesignals with FWHM and FSR of 0.8 nm and 5 nm could beobtained respectively. Digital codes can be generated andtransmitted via communication networks systems such as timedivision multiple access (TDMA) using dark and bright solitonpulses with FHHM and FSR of 0.54 nm and 4.71 nm