 so of course we jumped at the chance!
So who are Swaledale Butchers?
Swaledale online butcher are a traditional butchers based in Skipton; Yorkshire Dales committed to producing high-quality meat. A whole-carcass company that breeds traditional livestock, concentrating on exceptional meat rather than quantity.
Ordering meat and poultry online is a hassle-free way of shopping for food, they're also great for trying new types of meats and cooking techniques. Plus, there's considerably less food wastage.
We found it super easy to order. There is so much choice, the meat is separated into the different animals where you will see exactly how much of the animal is used. There are also sections for specials, seasonal products and Meat Boxes.
We chose the Essential Meat Box to be able to try as many varieties of meat on offer as possible. The Essential Meat Box retails at £60.00 and contains.
Orders are prepared and shipped the next working day via DPD and were given a 1-hour time slot on the day of delivery. Everything was very well-packed in a double-walled cardboard box, all the packaging is 100% recyclable and developed for shipping meats and temperature-sensitive goods.
They also offer free delivery for orders over £60 and a loyalty scheme where you earn 5 points for every £1 spent which you can redeem at the checkout.
We were super empress with the quality of the meat. Swaledale pride themselves with their meat which is always fresh and never frozen. Being a sustainable company, they have built amazing with selected farms and local abattoirs, meaning all their local products are traceable and animals have a high level of warfare.
All the meats were all sealed and labelled correctly, the quality is spot on. We could really taste the difference from our normal supermarket brought meat.
To date we have not eaten all of our order as there is only two of us, we cannot wait to have the Topside Beef Joint for our Sunday Roast using our Air fryer. The box is great value for restaurant quality free-range meat and poultry.
*Thank you to Swaledale for the opportunity to taste and review their delicious products. This is not a paid post, although we were sent a rather generous selection of quality meat to review.Björn Maes, et al.
R.J.P. Engelen, et al.
Guilin Sun, et al.
Photonic crystals [1] (PhCs) exhibit the unique potential to manipulate the flow of light at the wavelength scale and ultimately fabricate highly integrated optical devices [2]. PhCs consist of periodic arrangements of dielectric materials. With the proper geometric and material properties, a range of optical frequencies is forbidden to propagate for all possible crystallographic directions: a photonic bandgap. By selectively changing the local geometry of the PhC, localized states can be created. Specifically, an ordered series of defects can act as a waveguide for light, at otherwise forbidden frequencies [3, 4]. In practice, photonic crystal waveguides (PhCWs) are generally created in planar structures, where one is able to tailor the dispersion relation and hence properties like group velocity and transmission and reflection spectra [5, 6, 7, 8, 9, 10].
In a PhCW, the propagation of light is governed by Bloch’s theorem due to the interplay between the light and the surrounding periodic structure [11]. Experimentally, this Bloch wave character of a PhCW mode has been deduced by detecting the out-of-plane leakage of light [12]. Using far-field input-output methods also modified transmission characteristics, pulse dispersion, and group-velocity alteration have been studied [7, 8]. However, an important drawback of these approaches is that the PhCW dispersion relation is averaged throughout the full length of the PhCW. As a result, any local information on the non-radiative modes within the PhCW is lost in input-output methods. The full picture can only be acquired by probing locally along the PhCW. Indeed recently, PhCW dispersion has been addressed by local evanescent field probing. This was demonstrated by either investigating the evanescent field coupling between a tapered optical fiber and a PhCW [13] or by local near-field probing of the intensity distribution in a PhCW [14]. Unfortunately, in both cases only a small portion of the total band diagram was obtained.
Here we present the full band structure of a PhCW by employing a truly field sensitive near-field optical microscope. By probing both the local phase and amplitude of the light propagating, the full range of wavevectors in the PhCW can be uncovered [15]. The dispersion relation of the PhCW is experimentally determined and allows the various modes to be discriminated by their propagation mode. The propagation of light through a single-line defect is studied. This simple geometry allows an accurate comparison between theory and experiment. Moreover, the frequency dependence of the group velocity (group velocity dispersion) of the bandgap guided mode is investigated, demonstrating the anomalous dispersion of the photonic crystal waveguide mode.
The photonic crystal waveguide consists of a silicon nitride membrane containing a hexagonal lattice of air holes. One row of holes is not perforated in the close-packed crystal direction (Γ-K). This specific linear arrangement of defects is commonly referred to as aW1 waveguide. Fabrication details can be found elsewhere [16]. The resulting structure is an air-bridge photonic crystal slab of silicon-rich nitride (n=2.16) of 160 nm thickness, 293 nm lattice periodicity (a) and a hole radius of 100 nm (0.34a).
The geometric parameters of the PhCW have been determined experimentally and are used to calculate the photonic band diagram of the PhCW. The results of a 3D FDTD simulation are presented in Fig. 1, for TE and TM polarized modes. In the crystal region, a PhC bandgap opens up in the visible spectrum for TE polarization (E-field in the plane of the crystal). Within the TE bandgap (λ=575-690 nm) two defect modes are allowed to propagate. For the TM-polarization, no bandgap exists and light can only be confined to the waveguide by refractive index contrast, both in-plane and out-of-plane. By selecting only the modes with a high quality factor from the FDTD simulation, two TMmodes are found. Both modes show good correspondence to a ridge-waveguide approximation, were one mode is confined to the waveguide and the other mode propagates within the slab. Therefore we assign the suggested modes to purely index-guided modes. These index-guided modes are highlighted by the red lines in Fig 1(b). However, for PhCW modes, it is probable that mini-stopgaps exist. These avoided crossings can in principle not be observed in the ridge-waveguide approximation.
Femtosecond laser pulses (250±50 fs, near-Fourier limited) are provided by a frequency doubled Ti:Sapphire laser pumped optical parametric oscillator. This versatile laser system with tunability from 597 up to 675 nm enables a large part of the bandgap to be investigated. The laser light was coupled into the W1 waveguide by a 0.4 NA objective. In order to obtain the complete band diagram in the first experiment, both TE and TM polarized light were coupled in. For the measurements on group velocity dispersion, the TE polarization is selected.
In our near-field experiments an aluminum-coated fiber probe with a sub-wavelength aperture of approximately 90 nm is used to pick up the light from the structure. The optical field is recorded while scanning over the sample. The fiber probe is kept in close proximity (2–20 nm) to the PhCW surface by a shear-force feedback mechanism based on a tuning fork sensor. In this proximity region, the local evanescent field tail of the light propagating in the photonic structure is coupled to the probe. The collected light is mixed with a reference beam in a heterodyne interferometric arrangement. This way, the interference between the two branches is obtained, which allows both phase (ϕ) and amplitude (A) to be determined [17]. As raw data, the optical measurement yields the spatial distribution of Acosϕ and Asinϕ. From these two parts of the raw data, the spatial amplitude distribution is calculated.
Also for a pulsed source we obtain the interference of the pulses, provided the collected and reference pulse overlap in time when they are mixed. In previous work [18, 19, 20], the arrival time of the reference pulse is fixed, i.e. the length of the reference branch is fixed while scanning an image. Thus a scan results in the spatial distribution of the interference. By varying the length of the reference branch between images, we can control the position of the interference maximum and thus track the femtosecond pulse through the PhCW.
In Fig. 2, the results of a near-field measurement at λ=674 nm (ω=0.435) is depicted together with the corresponding electron micrograph of the PhC structure as a reference. The propagation of light within the PhCW is clearly visible in the field amplitude distribution as a bright horizontal line in Fig 2(c). On close examination of the optical field in the waveguide, the lattice periodicity can be recognized in the amplitude distribution. Another striking feature is the field amplitude modulation along the waveguide with a period of approximately 6 lattice spacings. The beat pattern indicates the presence of multiple modes in the waveguide. Note that due to the simultaneous detection of TE and TM polarized light, quasi-interference can be observed in the measurements between perpendicular polarizations [21]. Therefore, the amplitude modulations are not necessarily caused by modes of equal polarization.
Each mode has a different phase velocity with a corresponding periodicity of phase fringes and spatial wavevector. From the