The growth of multi-walled carbon nanotubes (MWCNTs) has been extensively studied using electron microscopy. The ex situ structural behavior was examined to investigate the growth of the MWCNTs under different environments and pressures using electron microscopy. The arc discharge plasma technique was applied to synthesize the MWCNTs by evaporating carbon through the arc plasma between two cylindrical graphite rods, with a background pressure of 10⁻² to 10² mbar, inside a vacuum chamber under different ambient environments. The results showed that long MWCNT structures were successfully grown. We suggest that the mechanism involves: (i) fullerene formation; (ii) the elongation of fullerenes; and (iii) the growth of MWCNTs. Agglomeration with other structures then forms MWCNT bundles. We note that the pressure and environment in the vacuum chamber can affect the structure of the MWCNTs.

The novel twisted ring resonator called add-drop Mobius microring resonator is introduced and modelled with the analytical solution of transfer matrix methods for the generation of optical bistability. Simulated results show that, the add-drop Mobius configuration provides greater phase shift due to the longer length of propagation per roundtrip than add-drop filter configuration. In add-drop Mobius system, drop port generated the optical bistable hysteresis loop with 19.25 mW output switching power and through port generated lower switching power as 5.55 mW. The drop port of the system is found as the suitable port for the operating the all-optical hysteresis switching.

The effect of temperature on double ring resonator (DRR) glucose sensing is investigate theoretically and proposed. Different from other optical resonator, the pulse laser is used as an input source and the vertical DRR configuration is used. The concept for pulse propagation is based on the split-step Fourier method. Result shows that the detection of glucose is measured by optical losses and the losses at 26oC are 1.86 dB at through and 0.93 dB at drop port, respectively. The performance of glucose sensing on DRR is degraded by temperature. Effect of temperature creates more losses which results total loss of 2.01 dB at through and 1 dB at drop port when temperature increase by 1oC.