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

Cleaning Germanium Lenses: Choosing the Best Method

Cleaning germanium lenses elements improves performance, providing proper materials, techniques and handling procedures are used to minimize the risk of damage.

CVI LASER OPTICS

Optics can be contaminated in many ways. Contamination can be kept to a minimum by returning the optics to their case after use or by covering the optics for protection from the outside environment. However, even with all these precautions, the optic will eventually accumulate dust, stains or some other form of contamination.

Inspection of germanium lenses surfaces

During inspection, all optics must be handled in the cleanest area available (preferably a cleanroom or within a laminar flow bench). Proper equipment, such as powder-free cleanroom gloves or finger cots must be worn at all times to avoid grease and oils from being transferred to the optic. Lens tissue paper, dust-free blowers, hemostats, cotton swabs, cotton tips, and reagent-grade acetone and methanol, will all be needed for cleaning optics. The acetone and methanol must be fairly fresh to avoid leaving any marks on the optics. Reagent-grade isopropyl alcohol can also be used instead of acetone.

Pro Tip: Clean optics against a dark background so dust can be seen and eliminated more efficiently.

There are two ways in which an optic can be evaluated:

• If the optic is being used in a laser-based system, contamination on the optic might cause the optic to scatter the laser light, thus reducing power and making the optic “glow.”

• An optic can also be visually inspected by holding it below a bright light source and carefully viewing it at different angles. This will cause the light to scatter off the contamination enabling the viewer to see the various stains and dust particles.

Cleaning methods

1) Blowing method
2) Drop and drag method
3) Wipe method
4) Bath method
5) Soap solution method
6) Ultrasonic cleaning method

Solvents

Historically, germanium lenses components such as mirrors and beamsplitters have been cleaned by hand, using lint-free germanium lenses wipes and reagent-grade acetone or another liquid solvent such as methanol, ethanol, 97 percent pure isopropyl alcohol, methyl ethyl ketone (MEK) or methylene chloride (MEC). Some inorganic acids such as trichloroethylene (TCE), hydrofluoric acid (HF) and hydrochloric acid (HCl) may be used on uncoated silicon wafers, and nitric acid may be used on germanium substrates. Acidic solutions, however, should never be used on coated or uncoated zinc sulphide (ZnS) or zinc selenide (ZnSe) components.

Acetone is very good at dissolving grease, but it dries very quickly and always should be handled with acetone-impenetrable gloves. In general, isopropyl alcohol is a safe and effective cleaner – except for cleaning aluminium coatings. Because alcohol reacts with aluminium, it should never be used on protected or bare aluminium-coated mirrors. Methanol and most acidic solutions can be toxic or damaging to optics or coatings if misused, so care should be taken to follow the instructions provided by the manufacturer.

Liquid CO2 is a new technique that is used to remove oils and microscopic particles from germanium lenses waveguides, electro-germanium lenses devices, silicon wafers and a variety of biomedical, aerospace and semiconductor components. This process delivers a precisely controlled and purified spray alternated with warm air cycles to the germanium lenses surface. Because CO2 is noncorrosive and relatively nontoxic, it is safer to use than many traditional solvents, but it requires nontraditional procedures and a controlled, moisture-free work environment and so may incur additional expenses. In the long term, however, it may turn out to be a less expensive and a more effective means of achieving ultraclean surfaces, possibly resulting in coatings with higher damage thresholds.

Storage conditions

Once you have cleaned the optic, place it in the mount it will be used in or wrap it in lens tissue and place it in its container right away. The proper container to use is a polycarbonate/PTFE/PET-G box, in a cleanroom environment. The room temperature should be kept between 15 and 25 °C (60 to 80 °F). Ideally, humidity should be controlled and kept below 30 percent.

CAUTION: Do not use a polypropylene box. Studies have shown that permanent outgassing of the storage box leads to adsorption of products detrimental to laser resistance of coated optics.

This article comes from photonics edit released

IR Windows Optics: What’s Available?

One of the first things we need to get our heads around when it comes to IR cameras, is what they can do and what they can’t. This will ultimately lead us to what an IR Windows Optics are and the crucial factors you must take into consideration when thinking about investing in them. One of which, considered the most important factor, is the “optic” material that they are manufactured from.

What is an IR camera?

An infrared, or IR camera is a very clever piece of technology in that it can actually see heat.

Some of you may recollect a very famous movie in which soldiers are seeking an extraterrestrial being using an infrared camera. Although there have been significant advances in the technology of IR, the functionality is demonstrated very well here.

The way that IR cameras work is that they use a completely different part of the electromagnetic (EM) spectrum to the part that the human eye uses. This is known as the infrared part of the electromagnetic spectrum.

The advances in microbolometer technology – which is essentially a sensor within a camera – makes the IR camera an exclusively ‘uncooled’ system. This is a relatively new form of sensor which comes with lots of advantages, including the fact that it removes the need of a cooler due to it’s runtime extension. These types of cameras tend to operate in what is known as the ‘longwave’ or 8-14μm section of the electromagnetic spectrum.

What materials can be used for an IR Windows optics?

IR Windows Optics– which are used to perform fast and safe infrared surveys of electrical equipment across all industry sectors – require certain materials that are transparent to infrared in the band that the particular camera you are using operates in. At the moment there are three different options of optic material that are typically available.

This article comes from cord-ex edit released

The nai scintillator efficiency of sodium and iodine recoils

Searches for weakly interacting massive particles that may constitute the Galactic dark matter can be based on the detection of nuclear recoil events in NaI scintillator detectors.

For this purpose it is necessary to know the relative nai scintillator efficiency for nuclear recoil events. Presented here are the results of measurements of the efficiency for conversion of low energy I and Na nuclear recoil events into nai scintillator light in NaI(Tl).

The experiments were performed using elastic scattering of monoenergetic neutrons of energy 3.2–5.5 MeV. The relative nai scintillator efficiency was found to be about 30% for Na recoils, down to 15 keV, and 8% for I recoils, down to 27 keV.

This article comes from sciencedirect edit released

Lithium Tantalate For Surface Acoustic Wave (SAW) Applications

Our lithium tantalate wafer production combines high quality wafer fabrication with the cost advantages of Chinese boule growth to add attractively priced lithium tantalate wafers to the quartz wafers already in our SAW product line. We modified the same high volume semiconductor based production line previously installed for quartz to the processing of lithium tantalate for SAW wafer applications.

We offer lithium tantalate wafers with typical specifications

  • 3-inch or 100-mm diameter
  • 0.25 – 0.50 mm thickness (thinner wafers under development)
  • 36o, 42o and X-cut orientations
  • fine-lapped back side
  • standard “white” wafers and “black” wafers with reduced pyroelectricity

We can accommodate a wide range of Curie temperature specifications (600oC – 610oC) as well as non-standard orientations and smaller diameter wafers. Also the degree to which the pyroelectric effect is reduced in “black” lithium tantalate can be varied to meet customer-specific needs. Wafers in the 0.18 – 0.20 mm thickness range and 150-mm diameter wafers are under development.

This article comes from sawyerllc edit released

Evaluation of the Detection Efficiency of LYSO Scintillator in the Fiber-Optic Radiation Sensor

Workers should take extreme care when approaching high radiation areas, such as areas neighboring highly radioactive equipment or spent fuel pool, due to the risks of radiation exposure. To detect the radiation levels in those areas, it is necessary to develop a remote radiation detection system. The radiation levels surrounding the spent fuel pool are generally measured using the fixed type radiation detector system. Sometimes, the radiation levels on the water surface of the pool need to be measured using a portable radiation detector that a worker brings to the measurement point.

The LYSO crystals have intrinsic radioactivity due to the Lu-176 isotope. 176Lu is a beta-emitter primarily decaying to an excited state of 176Hf. This isotope emits gamma photons with energies of 307 keV, 202 keV, and 88 keV. The crystal’s self-emission causes the crystal to be excited and produce scintillation light. This results in a self-count of 39 cps/g. From this, it was evaluated that the intrinsic radioactivity included in the LYSO scintillator used in this study contributed to 8~10% of the total counts.

Reviewing all the measurements shows that the differences in the detection efficiencies of the fiber-optic sensors were due primarily to the geometrical arrangements of fiber-optic sensors and radiation source and polishing of the fiber-optic sensors and the connecting conditions between the scintillator and transmitting fiber. The polishing of LYSO scintillator and transmitting and the connection between them were manually performed.

This article comes from hindawi edit released

Improvement of light extraction of LYSO scintillator

The self-assembled monolayer periodic array of polystyrene spheres conformally coated with TiO2 layer using atomic layer deposition is designed to obtain a further enhancement of light extraction for LYSO scintillator.

The maximum enhancement is 149% for the sample with polystyrene spheres conformally coated with TiO2 layer, while the enhancement is only 76% for the sample with only polystyrene spheres. Such further enhancement could be contributed from the additional modes forming by TiO2 layer due to its high refractive index, which can be approved by the simulation of electric field distribution. The experimental results are agreement with the simulated results.

Furthermore, the prepared structured layer exhibits an excellent combination with the surface of LYSO scintillator, which is in favor of the practical application. Therefore, it is safely concluded that the combination of self-assembly method and atomic layer deposition is a promising approach to obtain a significant enhancement of light extraction for a large area. This method can be extended to many other luminescent materials and devices.

This article comes from osapublishing edit released

Long-range MWIR zoom lens for surveillance and intelligence

Clear Align in Eagleville, Pa., is introducing the MirZ 8017 long-range midwave infrared MWIR zoom lens for MWIR cooled detectors in applications such as surveillance, intelligence, and border control.

The electro-optical lens can resolve small targets like lighted cigarettes at distances as far as 12 miles, and offers compensated performance over a continuous MWIR zoom range over focal lengths from 80 to 1365 millimeters.

Because of the infrared bandwidth, this lens works in conditions that stymie visible lenses: fog, smoke, haze, and air pollution, company officials say.

The MirZ 8017 is an IRZoom brand lens with a 17x continuous MWIR zoom capability with less than 0.65 percent distortion and resolution to 25 line pairs per millimeter.

Suitable for use with low-noise cooled detectors, the lens offers electronic MWIR zoom, focus, and thermal compensation calibrated over the its operating range so that focus is not lost as operating conditions are changed.

This article comes from military-aerospace edit released

Achromatic Wave

Achromatic wave is similar to zero order waveplate except that the two plates are made from different birefringent crystals, such as crystal quartz and magnesium fluoride.

Since the dispersion of the birefringence can be different for the two materials, it is possible to specify the retardation values at a wavelength range. From the curve, you can see that the bandwidth of such achromatic wave is very wide, while the achromatic wave remain a nearly constant retardance over a range of wavelength.

This article comes from wavelength-tech edit released