Gold cone metasurface MIC sensor with monolayer of graphene and multilayer of graphite

This report makes a comparison between the spectrum features of plasmonic metamaterial metal-insulator-conductor (MIC) sensor with a monolayer of graphene and another MIC sensor with a multilayer of graphite as the back reflector. In both structures, the silicon substrate as an insulator layer was sandwiched between sub wave length periodic nanogold cones as the first layer and graphene and graphite as the third layer, respectively. Nanolayer of chromium nano rods was also considered in the structure of MIC sensors as an interface layer between silicon and nanogold cone metasurface. The performance of the sensor was evaluated under different incident polarized light angles and different thickness of the metasurface when the metasurface infiltrated with seawater and air. The transmission spectrum of monolayer graphene-based MIC sensor, respecting to s-polarized waves, reveals prominent feature to detect the air rather than seawater in invisible regime. Meanwhile, the reflection spectrum of graphite-based MIC sensor provides ∼0 % reflection under resonance condition regarding s- and p-polarized waves for detecting air in visible spectrum

Dual-wavelength fiber lasers covering the regions of 1.0, 1.5 and 2.0 micron and their applications / Seyed Mohammad Reza Khalifeh Soltanian

This report describes the methods and processes of generating tunable dual-wavelength fiber lasers by using three different types of gain media covering three different regions of 1, 1.5 and 2 micron, and an investigation regarding their applications. The homogeneous gain media used in the 1, 1.5, and 2 micron region are ytterbium-doped fiber (YDF), erbium-doped fiber (EDF), and thulium-doped fiber (TDF) respectively. Dual-wavelength fiber laser (DWFL) designs using a selective element, such as photonic crystal fiber (PCF), I discussed in the report in terms of their output power, side mode suppression ratio (SMSR) and tunability. Dual-wavelength fiber laser generation in three different homogeneous medium has been achieved and discussed. Strong mode competition induced by homogeneous broadening represents the main challenge for achieving stable multi-wavelength oscillation at room temperature. By controlling the spatial hole burning, spectral hole burning and polarization states of the modes in the ring laser cavity, new and novel approaches can be proposed to overcome the mode competition issue faced by homogeneous medium for generation of balanced dual-wavelength output. Moreover, modes propagation in PCF is investigated both experimentally and via modeling to attain a deep understanding about the physics behind the generation of DWFL. The modeling results of the field profiles for the fundamental quasi-TM modes are calculated with the vector beam propagation method (BPM). The DWFLs have numerous applications in various fields including fiber sensors and communications. In this study, new designs of DWFLs for various applications are presented and demonstrated. The single longitudinal mode (SLM) properties of the generated DWFL are also investigated and demonstrated. Potential application of DWFL for terahertz rays, the generation of dual-wavelength Q-switched fiber laser, and also the generation of DWFL for microwave generation are presented. All these applications result from the high stability and excellent quality of the fiber laser in terms of output powers and high value of SMSR

Multi wavelength mode-lock soliton generation using fiber laser loop coupled to an add-drop ring resonator

The add-drop ring resonator system is the fundamental building block of optical transmission and communication systems. An add-drop microring resonator (MRR) consist-ing of a 120 µm diameter loop of optical waveguide was used to filter the input spectrum of a mode-locked laser. The experimental setup is used to generate soliton mode-locked laser pulse, where we used the experimental data to model and simulate the propagation of the mode-locked soliton laser pulse within the MRR. The transmission characteristics of the through and drop ports output signals from this system are described in this paper. As results, multi-wavelength mode lock soliton with full width at half maximum and free spectral range (FSR) of 8 pm and 0.67 nm were generated respectively. The FSR of the input signals are enlarged significantly by the system, thus separating signal wavelengths by a resonator has been investigated. In the proposed scheme, FSR-spaced signals are leveraged as a means of obtaining higher bandwidth output signals while using an add-drop MRR

All optical ultra-wideband signal generation and transmission using mode-locked laser incorporated with add-drop microring resonator

The novel technique for generating the robust, ultra-wideband (UWB) signal in the optical domain using a mode-locked laser incorporated with an add-drop microring resonator filter is presented. In order to enable the down conversion of the UWB signal to the RF domain, two wavelength ranges 1553.72 and 1553.92 nm, which are 24.65 GHz apart from each other, are used. These wavelengths were generated based on a single longitudinal mode (SLM) dual-wavelength fiber laser in a laser ring cavity. The upper wavelength of the generated dual-wavelength laser is modulated with the UWB spectrum using an optical carrier suppression (OCS) scheme and the lower wavelength is kept unmodulated. After beating the modulated and unmodulated wavelength by launching into the photodiode, the 24 GHz UWB signal can be generated to be applied to UWB over fiber (UWBoF) technology. The error vector magnitude (EVM) for the signal transmission was calculated and the EVM below 10% is achieved for 25 Km optical and 20 m wireless link

Generation of femtosecond soliton tweezers using a half-panda system for modeling the trapping of a human red blood cell

Femtosecond optical tweezers are an effective tool for handling individual human red blood cells, as they allow for comparatively easy single cell manipulation with consequent diverse applications in biological science. Optical trapping at low power with short exposure time is desired in order to minimize damage in the vicinity of targeted tissue, and such a requirement can be achieved by using micro-ring resonators in an optical tweezers configuration. This paper describes a modified add/drop multiplexer system, known as half-panda ring resonator, which is suitable for human blood cells trapping and deployment during investigations on deformation and vibration behavior of biological cells. Dark-bright solitons and Gaussian beams are propagated within the proposed system, while the output features can be controlled via manipulation of specific parameters. This study details optical tweezers of FWHM of 33 and 100, and 90 and 152 femtoseconds that are generated at the drop and through ports of the system respectivel

Increment of access points in integrated system of wavelength division multiplexed passive optical network radio over fiber

This paper describes a novel technique to increase the numbers of access points (APs) in a wavelength division multiplexed-passive optical network (WDM-PON) integrated in a 100 GHz radio-over-fiber (RoF). Eight multi-carriers separated by 25 GHz intervals were generated in the range of 193.025 to 193.200 THz using a microring resonator (MRR) system incorporating an add-drop filter system. All optically generated multi-carriers were utilized in an integrated system of WDM-PON-RoF for transmission of four 43.6 Gb/sec orthogonal frequency division multiplexing (OFDM) signals. Results showed that an acceptable BER variation for different path lengths up to 25 km was achievable for all four access points and thus the transmission of four OFDM channels is feasible for a 25 km standard single mode fiber (SSMF) path lengt

Towards 5G: a photonic based millimeter wave signal generation for applying in 5G access fronthaul

5G communications require a multi Gb/s data transmission in its small cells. For this purpose millimeter wave (mm-wave) RF signals are the best solutions to be utilized for high speed data transmission. Generation of these high frequency RF signals is challenging in electrical domain therefore photonic generation of these signals is more studied. In this work, a photonic based simple and robust method for generating millimeter waves applicable in 5G access fronthaul is presented. Besides generating of the mm-wave signal in the 60 GHz frequency band the radio over fiber (RoF) system for transmission of orthogonal frequency division multiplexing (OFDM) with 5 GHz bandwidth is presented. For the purpose of wireless transmission for 5G application the required antenna is designed and developed. The total system performance in one small cell was studied and the error vector magnitude (EVM) of the system was evaluated

Carriers generated by mode-locked laser to increase serviceable channels in radio over free space optical systems

Mode-locked optical carriers with applicability for radio over free space optics (RoFSO) systems have been produced via a ring laser cavity incorporating an add/drop filter. This technique of generation allowed for servicing of a greater number of channels in a wavelength-division multiplexing RoFSO system, and the carriers were able to travel in a free space channel with very little dispersion. Sixteen carriers, having a free spectral range (FSR) of 12.5 GHz and full-width at half-maximum (FWHM) of 250 MHz, were created. Eight of these 16 generated carriers were then separately modulated with eight orthogonal frequency-division multiplex signals and subsequently optically multiplexed and transmitted to a free space optic (FSO) channel using an FSO antenna. At the receiver side, the received signal was demultiplexed, and the performance of the system was analyzed via calculating the error vector magnitude and constellation diagram of the entire system

Gold cone metasurface MIC sensor with monolayer of graphene and multilayer of graphite

This report makes a comparison between the spectrum features of plasmonic metamaterial metal-insulator-conductor (MIC) sensor with a monolayer of graphene and another MIC sensor with a multilayer of graphite as the back reflector. In both structures, the silicon substrate as an insulator layer was sandwiched between subwavelength periodic nanogold cones as the first layer and graphene and graphite as the third layer, respectively. Nanolayer of chromium nanorods was also considered in the structure of MIC sensors as an interface layer between silicon and nanogold cone metasurface. The performance of the sensor was evaluated under different incident polarized light angles and different thickness of the metasurface when the metasurface infiltrated with seawater and air. The transmission spectrum of monolayer graphene-based MIC sensor, respecting to s-polarized waves, reveals prominent feature to detect the air rather than seawater in invisible regime. Meanwhile, the reflection spectrum of graphite-based MIC sensor provides ∼0 % reflection under resonance condition regarding s- and p-polarized waves for detecting air in visible spectrum

Multiwavelength generation using an add-drop microring resonator integrated with an InGaAsP/InP sampled grating distributed feedback

A system of an add-drop microring resonator integrated with a sampled grating distributed feedback (SG-DFB) is investigated via modeling and simulation with the time-domain traveling wave (TDTW) method. The proposed microring resonator comprises a SiO2 waveguide integrated with an InGaAsP/InP SG-DFB, and the SiO2 waveguide consists of a silicon core having a refractive index of 3.48 and Kerr coefficient of 4.5 × 10-18 m2/W. The SG-DFB consists of a series of grating bursts that are constructed using a periodic apodization function with a burst spacing in the grating of 45 μm, a burst length of 5 μm, and 10 bursts across the total length of the SG-DBR. Transmission results of the through and drop port of the microring resonator show the significant capacity enhancement of the generated center wavelengths. The Q-factor of the microring resonator system, defined as the center wavelength (λ0) divided by 3 dB FWHM, without and with integration with the SG-DFB is calculated as 1.93 × 105 and 2.87 × 105, respectively. Analysis of the dispersion of the system reveals that increasing the wavelength results in a decrease of the dispersion. The higher capacity and efficiency are the advantages of integrating the microring resonator and the InGaAsP/InP SG-DFB