GGG crystal wafers and Substrates

● Fine mechanical, optical and chemical properties
● Excellent as optical, microwave isolator and HTS substrates

GGG crystal wafers is material with good optical, mechanical and thermal properties which make it promising for use in fabrication of various optical components as well as substrate material for magneto – optical films and high – temperature superconductors. It can be used for infrared optical isolator (1.3 and 1.5 um), which is made of YIG or BIG film on the Gadolinium Gallium Garnet (GGG) substrate plus birefringence parts. GGG crystal wafers is an important substrate for microwave isolators and can be used as a HTS material, for laser technology, telecommunications, electronic.

A Small-Animal PET System Based on LYSO Crystal Arrays

A positron emission tomography system for small animals has been designed for research purposes. Its detection modules are based on pixelated scintillator LYSO crystal arrays coupled to Hamamatsu H8500 position-sensitive photomultiplier tubes. The front-end electronics are based on nuclear instrumentation modules (NIM) and in-house built readout circuits. Peak signal digitization is performed with a commercial analogue-to-digital acquisition (DAQ) board.

The system has been characterized for spatial, timing and energy resolution, system dead time, absolute sensitivity, scatter fraction and noise equivalent count rate (NEC).

The results indicate that the detection modules are able to identify individual crystals (out of 400) with up to 8-to-1 peak-to-valley ratios with individual crystal energy resolution ranging from 7 to 15% at 511 keV. The timing resolution is 1.9 ns and the system dead time was found to be 16.8 ¿s and 42.1 ¿s for 0.5 ml and 10 ml volume sources, respectively. The measured absolute system sensitivity is 0.11% and the scatter fraction from a glass capillary inside a 2.5 cm diameter mouse phantom is 21.5%. A true NEC maximum value was not achieved with the system due to saturation of the PS-PMT output signals for activities above 0.27 mCi. Results from a Na18 F PET bone scan of a 30 g mouse are shown.

This article comes from ieeexplore edit released

Round Thin Film Laser Polarizers

  • Provide the achievement of strictly linear polarization of laser radiaton
  • Utilize the polarization wich occurs on reflection from a plane surface
  • Rs/Tp:>99.5/95.0% for standard thin film polarizers
  • Rs/Tp:>99.5/99.0% for high transmittance thin film laser polarizers
  • Ts<0.2%, Rp<0.2% for ultra high transmission thin film polarizers
  • Tp>98%, Ts<0.1% for thin film polarizers with high extinction ratio
  • High damage threshold reaching 10 J/cm2
  • Extinction ratio 200:1 (for standard, high and ultra high transmission thin film polarizers), 1000:1 (for thin film laser  polarizers with high extinction ratio)

Thin Film Laser Polarizers separate the s- and p-polarization components. They are designed for use in high energy lasers. Due to high damage threshold, reaching 10 J/cm2 @ 1064 nm 8 ns, Thin Film Polarizers are used as an alternative to Glan Laser Polarizing Prisms or Cube Polarizing Beamsplitters.

Typical applications are intracavity Q-switch hold-off polarizer or extracavity attenuator for Nd:YAG lasers.

Thin Film Polarizers can be used at an > 40° angle of incidence, but polarization is most efficient and appears in a broad wavelength range at 56° AOI (Brewster angle). Typical polarization ratio Tp/Ts is 200:1.

Standard size is up to Ø50 mm (2”), while max. available dimensions are 100×200 mm. For optimal transmission a Thin Film Polarizer should be mounted in an appropriate holder for angular adjustment. For Rectangular Thin Film Polarizers, visit here.

This article comes from eksma edit released

Intracavity PPLN crystals for ultra-low-voltage laser Q-switching and high-efficiency wavelength conversion

We report to the best of our knowledge the lowest switching voltage in an electro-optically Q-switched Nd:YVO4 laser by using a 13-mm long, 14-μm-period PPLN crystal as a Pockels cell. A switching voltage as low as ∼50 V in the PPLN crystal was sufficient to hold off the lasing of the Q-switched laser at a pump power more than two times above its continuous-wave threshold. When the PPLN Q-switch was driven by a 100-V voltage at 6.5 kHz, we obtained 0.9-kW laser peak power from this 1-W diode-pumped Nd:YVO4 laser system with 13% output coupling. When the PPLN Pockels cell was cascaded with a 5-cm long, 30-μm-period PPLN crystal, we produced ∼μJ/pulse energy at 1.59 μm from optical parametric generation inside the actively Q-switched laser.

This article comes from springer edit released

General properties of CdWO4 scintillator

Cadmium Tungstate (CdWO4) is a scintillation crystal with extremely low afterglow, good radiation resistance, high density and high Z value, low decay time also with relatively high light output.

CdWO4 scintillators was produced by using the Bridgman technique since 2011, with the maximum crystal boule size at ∅ 80 mm x 200 mm, which can be manufactured into the target sizes, besides the single crystals, we also have the capability to fabricate it into linear or 2 dimensional array used in the X ray security inspection systems.

CdWO4 scintillators is characterized by high density, high atomic number and relatively high light yield with extremely low decay time. and the afterglow of CdWO4, when subjected to x-ray irradiation, is very slow typically less than 0.1% after 3 ms, and demonstrate very good resistance. All of these features are significant and make CdWO4 a primary scintillation crystal for X ray computed Tomography(X-CT) and in security inspection.

This article comes from epic-crystal edit released

Germanium Lenses

Our Germanium lenses are perfect for Mid-Infrared applications. These lenses stand up well to harsh environments and we offer the most popular sizes with Anti-Reflection Coatings. Germanium is subject to thermal runaway, meaning that the transmission decreases as temperature increases. As such, these lenses should be used at temperatures below 100°C. Germanium’s high density (5.33 g/cm3) should be considered when designing for weight-sensitive systems. The Knoop Hardness of Germanium is 780, making it ideal for IR applications requiring rugged optics.

GERMANIUM LENSES

  • High Index of Refraction
  • Minimal Chromatic Aberration Due to Low Dispersion
  • Perfect for Rugged IR Applications
  • Popular Sizes Available with AR Coating from 3-12μm

Factory Standard– Contact us for manufacturing limit or custom specifications

  • Substrate Material: Ge (Germanium)
  • Diameter:  5mm-350mm
  • Shape: Spherical Plano-Concave, P-Convex, Concave-Convex or Aspheric
  • Focal length: +/-1%
  • Surface Quality: 20-10(after coating)
  • Surface figure: l/4 @ 633nm
  • Clear Aperture: >85% of central dimension
  • Antireflection Coating: @ 3-12 um

Further study of CdWO4 crystal scintillators as detectors for high sensitivity double beta experiments

Energy resolution, light yield, non-proportionality in the scintillation response, alpha/beta ratio, pulse shape for gamma rays and alpha particles were studied with CdWO4 crystal scintillators.

Some indication for a difference in the emission spectra for gamma rays and alpha particles was observed. No dependence of CdWO4 crystal pulse shape on emission spectrum wavelengths under laser, alpha particles and gamma ray excitation was observed.

Dependence of scintillation pulse shape for gamma quanta and alpha particles and pulse-shape discrimination ability on temperature was measured in the range of 0-24 degrees.

This article comes from arxiv edit released

Crystal growth of strontium titanate SrTiO3

SrTiO3 crystals have been prepared by flame-fusion growth and from KF-LiF and K-Li-borate fluxes.

The crystals are characterized by EPR, absorption spectra, chemical analyses and 7-rocking curves, and the structural perfection of flame-fusion and flux-grown crystals is compared.

This article comes from tandfonline edit released

UV Range Stepped Neutral Density on fused silica for full uv range control

We custom and standard neutral density optical filters for a wide spectrum of applications. These include machine vision, HPLC, gas chromatography, instrument calibration and flourescence microscopy.

Our online catalog continues to grow. The listed bandpass, longpass, shortpass, and neutral density optical filters are just a few in our expanding inventory. Please call or email us if you don’t see the filter you need. Our goal is to provide you with a perfect filter solution for your product or research project.

Our flexibility to run small prototype lots and custom setups at low cost have helped companies develop their products using our neutral density optical filters.

This article comes from maierphotonics edit released

Crystal optics

Compared to the previous options, this product has many benefits that far outweigh its failings. In our opinion, this is the best solution to go for when choosing IR Windows optics.

There are many different types of crystal IR Window materials. The most common being germanium. This material is found on your infrared camera lens and can either be purple or orange in colour, depending on the coating that has been used.

Germanium is known in the industry as the ‘grey transmitter’, which means that its transmission loss is consistent across the whole of the infrared spectrum. This factor makes it fantastic for lenses as it modulates the IR signal the same way regardless of wavelength. Also, the addition of anti-reflective coatings (AR) makes windows manufactured from this material extremely good infrared transmitters. Unfortunately, germanium can be expensive, and using this material to manufacture a 4″ IR Window would mean they would would end up retailing over $2000 per unit, which rules it out.

Another material which can be used is sapphire, which is very durable and would be able to withstand a hammer impact. But, similar to germanium, this is still a very costly material.

This leaves two materials, which are both ‘flourides’ – Calcium Flouride (CAF2) and Barium Flouride (BAF2). Both of which have been used as optics in the past, but although BAF2 is highly transmissive and great for measurement, it can also be susceptible to moisture and somewhat toxic.

CAF2 is the least expensive option here and is the optimum IR Window optic material. Although it can be brittle, properly coated CAF2 optics do not degrade over time and any errors in reading caused by the optic can be corrected reliably and repeatedly with a properly configured infrared camera. Taking all of this into consideration, we prefer HydroGARD coated CAF2 over the other options as the positives far outweigh the negatives.

Carbon Flouride is homogenous, meaning that its transmission characteristics are consistent across the face of the IR Window. This means that a properly configured IR camera can correct any errors and provide the thermographer with a truly representative temperature measurement. This material is also optically and thermally transparent and is not only transmissive to IR and visual cameras, but to UV cameras as well.

This article comes from cord-ex edit released