We present the design, fabrication, and characterization of InGaAs channel high electron mobility transistors (HEMTs) with ultralow contact resistance for millimeter-wave and subterahertz applications. The HEMT has a composite InGaAs channel and a 50-nm T-shaped gate, which was realized through a single-step electron beam lithography (EBL) process. A room temperature ohmic contact fabrication process achieving the lowest contact resistance of 15 m Omega.mm has been developed with all room temperature process. The I-V measurements of the HEMTs at room temperature revealed a peak drain current of 0.75 A/mm and a transconductance of 1.4 S/mm. In standard 50-Omega S -parameter measurements, the HEMTs exhibited a maximum gain of 10 dB at 170 GHz. However, utilizing an active load-pull measurement, the 50-nm HEMT shows a gain of 14.5 dB at 170 GHz and 2 dB at 270 GHz. The load-pull measurements also obtained power added efficiency (PAE) and 1-dB compression point of the HEMTs. The noise performance was characterized using a noise parameter system with source tuner between 2 and 50 GHz. A drift-diffusion model was used to benchmark the dc and RF performance of the devices, and good agreements have been achieved.

The finite size of 2D photonic crystals results in them being a lossy resonator, with the normally emitting modes of conventional photonic crystal surface emitting lasers (PCSELs) differing in photon lifetime via their different radiative rates, and the different in-plane losses of higher order spatial modes. As a consequence, the fundamental spatial mode (lowest in-plane loss) with lowest out-of-plane scattering is the primary lasing mode. For electrically driven PCSELs, as current is increased, incomplete gain clamping results in additional spatial (and spectral) modes leading to a reduction in beam quality. A number of approaches have been discussed to enhance the area (power) scalability of epitaxy regrown PCSELs through careful design of the photonic crystal atom1–3. None of these approaches tackle the inflexibility in being unable to independently modify the photon lifetime of the different modes at the Γ2 point. As a method to introduce design flexibility, resonator embedded photonic crystal surface emitting lasers (REPCSELs) are introduced. This device, combining comparatively low coupling strength photonic crystal structures along with perimeter mirrors, allow a Fabry–Pérot resonance effect to be realised that provides wavelength selective modification of the photon lifetime. We show that surface emission of different surface emitting modes may be selectively enhanced, effectively changing the character of the modes at the Γ2 point. This is a consequence of the selective modification of in-plane loss for particular modes, and is dependent upon the alignment of the photonic crystal (PhC) band-structure and distributed Bragg reflectors’ (DBRs) reflectance spectrum. These findings offer new avenues in surface emitting laser diode engineering. The use of DBRs to reduce the lateral size of a PCSEL opens the route to small, low threshold current (Ith), high output efficiency epitaxy regrown PCSELs for high-speed communication and power sensitive sensing applications.

We demonstrate the fabrication of sub-100 nm T-Gate structures using a single electron beam lithography exposure and a tri-layer resist stack - PMMA/LOR/CSAR. Recent developments in modelling resist development were used to design the process, in which each resist is developed separately to optimise the resulting structure. By using a modelling approach and proximity correcting for the full resist stack, we were able to independently vary gate length (50-100 nm) and head size (250-500 nm) at the design stage and fabricate these T-Gates with high yield.

Resonator embedded photonic crystal surface emitting lasers are reported. Reduced threshold current and enhanced slope efficiencies are demonstrated in InP-based 1310nm PCSELs. Band-structure analysis of 1550nm devices demonstrates that frequency selective cavity enhancement of band-edges (and hence lasing mode selection) may be obtained.

To study linguistics is to gain a greater understanding of a fundamental part of what it means to be human. Linguistics is a scientific field and an academic discipline that has both theoretical and practical applications. Linguists study language structure at several theoretical levels that range in size from tiny units of speech sounds to the context of an entire conversation. Students of linguistics often begin with a basic understanding of each level of language, then specialize in one or more levels or in a practical application of linguistics. The smallest units of language are studied in the field of phonetics, which concerns itself with the individual sounds produced while speaking. Phonology takes a look at those small units of sound together in the context of whole utterances, and searches for patterns in sound across a language or a whole group of languages.

Electroabsorption modulated lasers (EMLs), comprising a distributed feedback (DFB) laser and electroabsorption modulator (EAM) monolithically integrated into the same chip, are attractive because of their compact size, low fabrication cost, and their capability to offer a high modulation speed with low drive voltage, low chirp, and high extinction ratio [1] , [2] . The modulation speed of the EML is limited by the RC constant of the EAM electrode, which is conventionally configured with either a lumped or travelling-wave (TW) electrode. The latter approach overcomes the RC limit by including the EAM in a microwave circuit matched to the source [3] . However, due to restrictions imposed by size and materials, TW EAMs have to date been integrated externally using a specifically designed material structure or monolithically using selective area growth.

This research focused on the language being used in Regulation Number 40 year 2007 regarding limited liability company in Indonesia and the data is taken from Regulation Number 40 year 2007 regarding limited liability company in Indonesia that is collected randomly so the technique that will be used in this research is the sampling technique, because the data was chosen randomly and the method that will be used to analyze the data is descriptive method because the data will be described descriptively. It will describe the reason why the translator use that kind of equivalence to translate Indonesian into the English language.

We report the engineering of air-voids embedded in GaAs-based photonic crystal surface emitting lasers realised by metalorganic vapour-phase epitaxy regrowth. Two distinct void geometries are obtained by modifying the photonic crystal grating profile within the reactor prior to regrowth. The mechanism of void formation is inferred from scanning transmission electron microscopy analysis, with the evolution of the growth front illustrated though the use of an AlAs/GaAs superlattice structure. Competition between rapid lateral growth of the (100) surface and slow diffusion across higher index planes is exploited in order to increase void volume, leading to an order of magnitude reduction in threshold current and an increase in output power through an increase in the associated grating coupling strength.

This paper analyzes 2D photonic crystal surface-emitting laser diodes with void-containing and all-semiconductor structures by comparing their simulated mode distribution, band structure, and coupling coefficients. A photonic crystal design with a square lattice and circle atoms is considered.

The use of imperative sentences is very important especially in attracting customers for any business. Especially for the business in the tourism industry how to attract customers is very important. That is why this research is very important to be conducted therefore the people who have I have businesses in the tourism industries know how to attract people using the imperative sentences in their website. The research will divide the imperative sentences into rationalization, identification, giving advice, confirmation, compensation, projection, and a replacement found on the website of the hotels and resorts in the village of Kenderan. It is found out that the hotels and resorts in the Village use these sentences to attract more visitors to stay in their hotel or resort. So it is suggested that the business owner, especially the owner of the hotels and feel like in this village. Keep using imperative sentences on the other website to attract more customers. For example, the technique of rationalization is very useful to attract more customers because the customer feels that they can feel or they image in the situation that they will have if they stay in the resort.

We present an InP-based epitaxially regrown photonic crystal surface emitting laser diode, operating under pulsed electrical drive at room temperature, and lasing at 1523 nm. This opens the route to the development of high efficiency InP based surface emitting lasers.

A compact silicon photonics multi-wavelength filter is demonstrated using superimposed sidewall Bragg gratings. We show arbitrary wavelength spacing with 8 superimposed gratings on a total footprint that is equivalent to a single Bragg grating device. Integrated waveguide Bragg gratings are one of the fundamental building blocks in the Photonic Integrated Circuit (PIC) designer’s toolkit. The concept of using the bandgap region of an inline grating device as a spectral filter is well established and has been used across material platforms for laser design [1], dispersion engineering [2] and sensing applications [3]. In the silicon-oninsulator (SOI) platform the high optical confinement of the mode to the grating area allows unprecedented control over the grating coupling coefficient and Bragg wavelength, producing a wide variety of filter designs in both amplitude and phase domains [4,5]. Furthermore the sinusoidal sidewall variation commonly employed to create the periodic grating function is easily implemented in standard nanofabrication lines and can be controllably engineered. Fig. 1: Schematic of a superposition grating with two separate grating periods. SEM images show the amplitude variation of the sidewall grating along the device length due to beating between the two grating periods. The devices presented here are made by superimposing up to 8 grating periods over a total device length of 200 μm. The simplest approach to achieving multiple filter bands in a single waveguide is by cascading individual gratings with variable Bragg wavelengths. This geometry, however, produces grating lengths of at least NxLg, where N is the number of required filter bands and Lg is the individual grating length. In this work we demonstrate an alternative superstructured Bragg grating device that exhibits multiple filter bands with arbitrary wavelength spacings and with a footprint equivalent to a single Bragg grating device. The superstructured grating design is similar in concept to the multi-exposure technique used in fibre grating designs. Single sidewall perturbation functions An(z) can be defined as simple sinusoidal variations that produce the usual Bragg grating response, where An(z)=ansin(2πz/Λn), and Λn is the Bragg grating period for the n th filter response. The summation of these individual sidewall perturbation functions, ∑ , produces a total sidewall perturbation function with N Fourier components that will create N grating responses within the same physical length as a classical single period grating. In addition, the extinction of the filters can be weighted using their individual perturbation amplitudes an. The device geometry is illustrated by the schematic of Fig.1 that shows the profile of the sidewall grating when two separate grating periods are superimposed. In this work several grating devices based on an 8-wavelength basis set were fabricated and characterised. Arbitrary combinations of these 8 basis functions were shown to match simulated results and underline the equivalence of this device to a cascade of individual filters. Fig. 2: Measured (blue curve) and simulated (red dotted curve) grating transmission spectra for two different superposition grating devices. The binary numbers indicate the gratings of the 8-basis wavelength set that were ‘on’ for each device. The results of Fig. 2 indicate that any arbitrary combination of filter wavelengths can be fabricated in a single superposition with excellent agreement to the designed transfer function. Furthermore, the total length of the grating device is only 200μm, which is far more compact than the equivalent serial grating geometry. In conclusion we have demonstrated a compact means by which to generate a multiwavelength filter with non-repetitive filter band positions. Up to 8 grating filter bands are demonstrated in 200μm long devices on a single silicon waveguide. This same approach can be easily extended to the design of more complex transfer functions with arbitrary filter wavelengths that exhibit different reflectivities, bandwidth and phase profiles.

We report the first demonstration of InAs FinFETs with fin width W-fin in the range 25-35 nm, formed by inductively coupled plasma etching. The channel comprises defect-free, lattice-matched InAs with fin height H-fin = 20 nm controlled by the use of an etch stop layer incorporated into the device heterostructure. For a gate length L-g = 1 mu m, peak transconductance g(m,peak) = 1430 mu S/mu m is measured at V-d = 0.5 V demonstrating that electron transport in InAs fins can match planar devices.

We report the first demonstration of InAs FinFETs with fin width Wfin in the range 25-35 nm, formed by inductively coupled plasma etching. The channel comprises defect-free, lattice-matched InAs with fin height Hfin = 20 nm controlled by the use of an etch stop layer incorporated into the device heterostructure. For a gate length Lg = 1 μm, peak transconductance gm,peak = 1430 μS/μm is measured at Vd = 0.5 V demonstrating that electron transport in InAs fins can match planar devices.

The performance of hybrid photovoltaic-thermal systems can be improved using PV cells that are specially designed to generate both electricity and useful heat with maximum efficiency. Present systems, however, use standard PV cells that are only optimized for electrical performance. In this work, we have developed two cell-level components that will improve the thermal efficiency of PV-T collectors, with minimal loss of electrical efficiency. These are a spectrally-selective low- emissivity coating to reduce radiative thermal losses, and a nanotextured rear reflector to improve absorption of the near- infrared part of the solar spectrum for heat generation.

We demonstrate a semiconductor PCSEL array that uniquely combines an in-plane waveguide structure with nano-scale patterned PCSEL elements. This novel geometry allows two-dimensional electronically controllable coherent coupling of remote vertically emitting lasers. Mutual coherence of the PCSEL elements is verified through the demonstration of a two-dimensional Young's Slits experiment. In addition to allowing the all-electronic control of the interference pattern, this type of device offers new routes to power and brightness scaling in semiconductor lasers, and opportunities for all-electronic beam steering.

Frequency (100 Hz ≤ f ≤ 1 MHz) and temperature (-50 ≤ T 20 °C) characteristics of low interface state density D it high-κ gate-stacks on n-InAs have been investigated. Capacitance-voltage (C-V) curves exhibit typical accumulation/depletion/inversion behavior with midgap D it of 2 × 10 11 and 4 × 10 11 cm -2 eV -1 at -50 °C and 20 °C, respectively. Asymmetry of low-frequency C-V curves and C-T dependence for negative voltage showing a sharp transition of ≅-20 dB/decade between low- and high-frequency behavior indicate surface inversion. An inversion carrier activation energy and an InAs hole lifetime of 0.32 eV and 2 ns have been extracted, respectively. Surface channel nMOSFETs with gate length L g = 1 μm, channel thickness = 10 nm, and equivalent oxide thickness (EOT) 1 ≤ EOT ≤ 1.6 nm have been fabricated. For EOT = 1 nm, a subthreshold swing S = 65 mV/decade, transconductance g m = 1.6 mS/μm, and ON-current I ON = 426 μA/μm at an OFF-current I OFF = 100 nA/μm (supply voltage V dd = 0.5 V) have been measured. Peak electron field-effect mobilities of 6000-7000 cm 2 /Vs at sheet electron densities of 2-3 × 10 12 cm -2 were obtained for EOT as small as 1 nm.