Mohd Saiful Dzulkefly Zan

Analysis of independent strain-temperature fiber Bragg grating sensing technique using OptiSystem and OptiGrating

In this paper, a combination of two simulation tools provided by Optiwave Systems Inc. is used to perform a remote fiber Bragg grating (FBG) based strain-temperature sensor setup. Two Gaussian apodized FBG sensors were designed and characterized by OptiGrating. The customized FBGs were incorporated into OptiSystem tool to perform the analysis. Full ability to utilize the combination to perform remote strain-independent temperature FBG setup was demonstrated. 1.2 pm/μstrain and 14.4 pm/°C sensitivities obtained for strain and temperature respectively.

A Novel Technique Employing Tapered Fiber Bragg Grating to Solve the Axial/Transverse Forces Crosstalk in Microsurgical Instruments

This paper demonstrates the capability of retinal microsurgical instruments constructed with customized fiber Bragg gratings (FBGs) sensors to completely decouple the transverse and axial force components. In contrast to the constantly shifting Bragg wavelength, FBG bandwidth can only be tuned when a nonuniform strain/temperature distribution is applied. Using a tapered FBG (TFBG) at the neutral axis of the instrument makes the bandwidth tune-ability possible by applying forces both transversely and axially, while the bandwidth of the outer/lateral standard FBG (SFBG) due to the fiber symmetry remains insensitive to axial forces. Therefore, the crosstalk (transverse forces) in the TFBG can be easily filtered out when mixed forces are applied simultaneously. Tapered fiber mode analysis is carried out to calculate the local modes and is used in the analytic coupled-mode solution. Transfer-matrix method, then, is developed to analyze the reflected spectrum of the TFBG. We provide a developed mathematical model algorithm to show how force vectors can be measured. Tuning the reflected bandwidth is directly corresponding to the amount of the reflected optical power. Thus, the results show that the simulated needle sensors are able to measure transverse and axial forces with a sensitivity of 0.049 and 0.0026 dBm/mN, while the SFBG is insensitive to the axial forces. This novel method is applicable for microsurgical applications, i.e., vascular and cochlear implant surgeries and catheterization procedures.

OXADMs: The next generation of optical switching devices

This paper introduces a new optical device model named as an optical cross add and drop multiplexer (OXADM) which has potential use in CWDM metro area networks. The device uses the concepts of combination of optical add/drop multiplexing and optical cross connect between two main transmission lines in order to implement the wavelength routing operation [10]. MEMS optical switches are integrated in the device to make it re-configurable. With excellent features, the device is particularly designed to improve network efficiency, flexibility and survivability [7][8]. The device can be used in point to point, ring or mesh network topology to provide functionality such as routing, supervision, transport, multiplexing and restoration of client digital signals processed predominantly in the optical domain [7]. The wavelengths on each optical trunk can be switched between each other while implementing add and drop functions simultaneously. The multiplexer has undergone performance test at 2.5 Gbps (OC- 48) with BER less than 10-9. The maximum length can be achieved by OXADMs is 71 km without amplification at insertion loss 6 dB. A comparison between OXADM with the previous devices such as, OXC, TRN and OXN is also been studied.

Analysis and simulation of time domain multiplexed (TDM) fiber Bragg sensing array using OptiSystem and OptiGrating

In this paper, a combination of two simulation tools provided by Optiwave Systems Inc. was used to perform time division multiplexing TDM based fiber Bragg grating (FBG) sensor for strain measurement application. Four FBG sensors were designed and characterized by OptiGrating and then incorporated into OptiSystem tool to perform the TDM-based simulations. Full ability to utilize the combination to perform TDM-FBG array setup along a 4-km fiber was successfully simulated and analyzed. It was found that the response signal power has linearly decreased with the increase in every 300 μstrain, with the slope of around −0.0027 a.u./μstrain.