JUST HOW STRONG ARE SAPPHIRE WINDOWS?

What are Sapphire Windows?
Sapphire Optics is a synthetically grown super hard material that is extremely durable and resistant to scratches. It second only to diamond in terms of its strength. Sapphire windows can withstand more than what quartz and conventional glass can, and at a fraction of the thickness. Sapphire crystals are “grown” in extremely hot ovens. The large, cylindrical boules are cut into sapphire rods, which are then sliced into thin discs, ground, and polished.

Uses of Sapphire Windows
Sapphire windows are used when sapphire’s unique properties – high strength, high scratch resistance, wide optical transmission band, extremely high melt temperature, high thermal conductivity, high electrical resistance and chemical inertness – are required.

Commercial Uses
There are many commercial uses for sapphire. Among the most commonly known are the sapphire display windows that are used to protect the phones’ optics. Newer iPhones use sapphire windows because their fracture toughness is roughly four times greater than Gorilla Glass, which is just strengthened conventional glass. Prior to the smartphone revolution, most consumers’ consumers’ experience of sapphire came from the displays used in most high-end watches.

Optics, Wafers and Crystals

A variety of Optics, wafers and crystals substrates are offered.. Optics products includes: blanks, lenses, windows, prisms and optics made from sapphires, optical glass materials, fluoride crystals and other optical materials., various type of filters for lasers, lighting and biochemical applications and the optical components for IPL equipments. Shalom EO also offers the SAW wafers and substrates made from piezo-electric crystals like LT, LN and quartz, and substrates made from crystals like MgO, GGG, SrTiO3, ect. . The customized optical components for your special applications are available.

Characteristics of compact detectors based on pixellated arrays

Results are presented on the preliminary evaluation of the pixellated NaI(Tl) crystal arrays for use in high-resolution small field-of-view gamma cameras. A prototype detector was developed using the pixellated NaI(Tl) arrays attached to a 5″ diameter position-sensitive photomultiplier tube (PSPMT). Two 5.3 cm square pixellated arrays from Saint-Gobain with pixel sizes of 1/spl times/1/spl times/6 mm and 2/spl times/2/spl times/6 mm were tested. A conventional charge division readout using a resistive chain was used with the PSPMT. The detector was tested using a uniform flood source and a /spl sim/0.8 mm diameter collimated Tc-99m source. The collimated source was scanned over both crystal arrays. The performance characteristics including spatial resolution, energy resolution and the ability to resolve the pixellated crystal elements were determined. The response of the pixellated detector was also measured. With the conventional resistive-chain readout the individual pixels were well resolved for the 2 mm pixellated crystal array but not for the 1 mm pixellated crystal array from the images of a uniform flood source. An average FWHM of 1.4 mm was obtained with a 0.8 mm diameter pencil-beam over the active crystal area for both crystal arrays. The energy resolutions from the individual pixels were 10.8% and 10.0% at 140-keV photon energy for the 1 mm and 2 mm pixellated crystals, respectively. Our study indicates that using conventional resistive-chain readout, a compact detector comprised of a pixellated NaI(Tl) crystal array and a 5″ diameter PSPMT at best can achieve a spatial resolution of /spl sim/1.1 mm. We conclude that the use of pixellated crystal arrays with /spl sim/1.5 mm pixel element is likely to be an optimal choice for the combination of this PSPMT with resistive chain readout technology for development of high resolution small field-of-view gamma cameras.

IR Lenses for Cooled Detectors

IR Lenses for MWIR Cooled Thermal Imaging Cameras
● Aspherical and binary optical technology adoped in design
● Various types of IR materials are used

Hangzhou Shalom Electro‐optics Technology Co., Ltd.

The lenses are designed and used in middle wavelength infrared range (MWIR) thermal imaging cameras of cooled FPA detectors at 3-5μm, with manual or motorized mechanism and in wide range of  focal length, the single FOV and double FOV lenses modules are available. The designed modules are
listed for your selection, and the customs modules are available for customer’s  request.

Modules or Types
The modules are designed for 320 x 256 – 30um/640 x 512 – 15um MWIR cooled detector at  3-5μm.

Features
1.  Aspheric Technology and Binary Optics Technology are used in design, which effectively reduce  the spherical aberration, distortion and other various aberrations, achieve athermalization design and  reduce the number of needed lens elements, lower the cost.

2. Various type of the infrared materials (like Ge, ZnSe, ZnS, AMTIR, CaF2, Sapphire, BaF2 ect.) are used in the lenses, which would successfully eliminate the aberration of the image and improve the quality of imaging, especially for the large diameter telephoto lenses.

3. Advanced equipment and machines are used to process the infrared materials optics: ultra-precision single point diamond processing machine to achieve the precision aspheric in 3nm, diffractive surface processing equipment to process the Ge, ZnSe, ZnS and AMTIR materials.

4. Different types of coating are made on the lens optics: high-efficiency anti-reflection coating (or high-efficiency AR), durable anti-reflection coating (or Durable AR) and diamond-like hard carbon coating(or DLC coating).

5. Complete quality assurance system
6. Within our quality system, we works out a series of specific craftworks and develops a strict test  procedure to guarrantee the quality of products.

Properties of scintillators

There are many desired properties of scintillators, such as high density, fast operation speed, low costradiation hardness, production capability and durability of operational parameters. High density reduces the material size of showers for high-energy γ-quanta and electrons. The range of Compton scattered photons for lower energy γ-rays is also decreased via high density materials. This results in high segmentation of the detector and leads to better spatial resolution. Usually high density materials have heavy ions in the lattice (e.g., leadcadmium), significantly increasing the photo-fraction (~Z4).[further explanation needed] The increased photo-fraction is important for some applications such as positron emission tomography. High stopping power for electromagnetic component of the ionizing radiation needs greater photo-fraction; this allows for a compact detector. High operating speed is needed for good resolution of spectra. Precision of time measurement with a scintillation detector is proportional to √τsc. Short decay times are important for the measurement of time intervals and for the operation in fast coincidence circuits. High density and fast response time can allow detection of rare events in particle physics. Particle energy deposited in the material of a scintillator is proportional to the scintillator’s response. Charged particles, γ-quanta and ions have different slopes when their response is measured. Thus, scintillators could be used to identify various types of γ-quanta and particles in fluxes of mixed radiation. Another consideration of scintillators is the cost of producing them. Most crystal scintillators require high-purity chemicals and sometimes rare-earth metals that are fairly expensive. Not only are the materials an expenditure, but many crystals require expensive furnaces and almost six months of growth and analyzing time. Currently, other scintillators are being researched for reduced production cost.

Several other properties are also desirable in a good detector scintillator: a low gamma output (i.e., a high efficiency for converting the energy of incident radiation into scintillation photons), transparency to its own scintillation light (for good light collection), efficient detection of the radiation being studied, a high stopping power, good linearity over a wide range of energy, a short rise time for fast timing applications (e.g., coincidence measurements), a short decay time to reduce detector dead-time and accommodate high event rates, emission in a spectral range matching the spectral sensitivity of existing PMTs (although wavelength shifters can sometimes be used), an index of refraction near that of glass (≈1.5) to allow optimum coupling to the PMT window. Ruggedness and good behavior under high temperature may be desirable where resistance to vibration and high temperature is necessary (e.g., oil exploration). The practical choice of a scintillator material is usually a compromise among those properties to best fit a given application.

Among the properties listed above, the light output is the most important, as it affects both the efficiency and the resolution of the detector (the efficiency is the ratio of detected particles to the total number of particles impinging upon the detector; the energy resolution is the ratio of the full width at half maximum of a given energy peak to the peak position, usually expressed in %). The light output is a strong function of the type of incident particle or photon and of its energy, which therefore strongly influences the type of scintillation material to be used for a particular application. The presence of quenching effects results in reduced light output (i.e., reduced scintillation efficiency). Quenching refers to all radiationless de‑excitation processes in which the excitation is degraded mainly to heat.[5] The overall signal production efficiency of the detector, however, also depends on the quantum efficiency of the PMT (typically ~30% at peak), and on the efficiency of light transmission and collection (which depends on the type of reflector material covering the scintillator and light guides, the length/shape of the light guides, any light absorption, etc.). The light output is often quantified as a number of scintillation photons produced per keV of deposited energy. Typical numbers are (when the incident particle is an electron): ≈40 photons/keV for NaI(Tl), ~10 photons/keV for plastic scintillators, and ~8 photons/keV for bismuth germanate (BGO).

Scintillation detectors are generally assumed to be linear. This assumption is based on two requirements: (1) that the light output of the scintillator is proportional to the energy of the incident radiation; (2) that the electrical pulse produced by the photomultiplier tube is proportional to the emitted scintillation light. The linearity assumption is usually a good rough approximation, although deviations can occur (especially pronounced for particles heavier than the proton at low energies).

Resistance and good behavior under high-temperature, high-vibration environments is especially important for applications such as oil exploration (wireline logging, measurement while drilling). For most scintillators, light output and scintillation decay time depends on the temperature. This dependence can largely be ignored for room-temperature applications since it is usually weak. The dependence on the temperature is also weaker for organic scintillators than it is for inorganic crystals, such as NaI-Tl or BGO. Strong dependence of decay time on the temperature in BGO scintillator is used for remote monitoring of temperature in vacuum environment. The coupled PMTs also exhibit temperature sensitivity, and can be damaged if submitted to mechanical shock. Hence, high temperature rugged PMTs should be used for high-temperature, high-vibration applications.

From Wikipedia, the free encyclopedia

Infared Spherical Lenses(Infared Spherical Lenses)

Hangzhou Shalom EO provides the spherical optical lenses used in thermal imaging cameras at wavelength range MWIR (3-5μm) and LWIR (8-12μm), the lenses are customized and made according to customer’s drawings and requirements. The plano-convex, plano-concave, double convex and meniscus lenses are available, the lens substrates are made from infrared materials: Ge, ZnSe, ZnS, CaF2, BaF2, GaAs, AMTIR glass, Si, Sapphire ect.

thermal imagings\optics for IR lenses\IR Spherical Lenses

 

Features

Optical Lenses works at MWIR (3-5μm) and LWIR (8-12μm) wavelength range;
Substrates materials: Ge, ZnSe, ZnS, CaF2, BaF2, GaAs, AMTIR glass, Si, Sapphire;
Various coating: high-efficiency AR, durable AR and DLC coating are available;
Specifications conformed to military standard.

Main elements of laser crystal

The activated ions used in the laser crystal(Hangzhou Shalom Laser Components) are mainly transition metal ions and trivalent rare earth ions. The optical electron of the transition metal ion is the 3d electron in the outer layer. In the crystal, the optical electron is directly affected by the surrounding crystal field, so the spectral characteristics of the crystal of different structure types are greatly different. The 4f electrons of the trivalent rare earth ions are shielded by the outer electrons of 5s and 5p, so that the effect of the crystal field is weakened, but the perturbation of the crystal field makes the 4f electron transition which is originally forbidden possible, resulting in narrow band absorption and fluorescence. Spectral line. Therefore, the spectrum of trivalent rare earth ions in different crystals is not as large as that of transition metal ions. The matrix crystals used in laser crystals are mainly oxides and fluorides. As a matrix crystal, in addition to its physicochemical properties, it is easy to grow large-size crystals with good optical uniformity, and it is cheap, but consider its compatibility with activated ions, such as the radius of the matrix cation and activated ions, and the electronegativity. Sex and valence should be as close as possible. In addition, the effect of the host crystal field on the activation ion spectrum is also considered. For some special-purpose matrix crystals, the addition of activated ions can directly produce lasers with certain characteristics. For example, in some nonlinear crystals, the activated ions generate laser light and can be directly converted into harmonic output through the matrix crystal. More used: Nd:YAG, Nd:YVO4

The origin and development of laser components

The origin and development of laser components

Hangzhou Shalom EO provides the crystals, optics and components used in the lasers, which includes: Laser crystalsnonlinear crystalsopticsPPLN crystalspockels cells and passive Q-switches, waveplates and polarizing optics. Beside the general lasers, optics and Components for femto-second lasers, CO2 lasers, deep UV lasers, ring laser gyro-scope are available. And the high precision optics for demanding applications are offered.

The light source required for fiber optic communication in laser devices should be a high-speed modulated light source to carry large-capacity information. Such as lasers and LEDs. The so-called “modulation” is to change the intensity of light, etc., according to the information to be transmitted, to carry information.

The light source required for fiber-optic communication should be a high-speed modulated light source to carry large-capacity information. Such as lasers and LEDs. The so-called “modulation” is to change the intensity of light, etc., according to the information to be transmitted, to carry information. In 1960, Maimen invented the ruby ​​laser. The difference between laser and ordinary light is that the laser has a very simple optical frequency and has a linear line. In optical, it is called coherent light, and it is most suitable for light source of optical fiber communication. The usual light frequency is very messy and it contains many wavelengths. The usual light frequency is very messy and it contains many wavelengths. The characteristic of coherent light is that the light energy is concentrated, and the divergence angle is small, which is approximately parallel light. After the invention of the ruby ​​laser, various lasers were born: gas lasers, such as helium neon lasers; solid-state lasers, such as YAG yttrium aluminum garnet lasers; chemical lasers; dye lasers. Among them, the semiconductor laser is most suitable for the light source of optical fiber communication. Its small size and high efficiency, its wavelength is suitable for the low loss window of the fiber. However, the manufacturing process of semiconductor lasers is very complicated, and it is necessary to epitaxially grow five layers of doped semiconductor on a substrate material of extremely high purity and defect, and then lithographically illuminate the micron-sized optical waveguide thereon, which has a difficulty compared with the optical fiber. Nothing more than that. In the late 1970s, a semiconductor laser with a long working life at room temperature was finally produced. In 1976, the world’s first practical fiber-optic communication line was established in Atlanta, USA. At this time, the semiconductor laser has not passed, and the light source is a semiconductor light-emitting tube. In the early 1980s, single-mode fibers and lasers were mature, and the superiority of fiber-optic communication capacity was gradually brought into play.
The light emitted by the semiconductor laser is pure, the energy is concentrated, and the beam is very thin. It can efficiently shoot into a single-mode fiber with a core diameter of only 8 microns. Today’s high-speed fiber-optic communication systems use semiconductor lasers as light sources.

Hangzhou Shalom CaF2(Eu) Scintillators

Scintillators >> Scintillation Crystal Materials >> CaF2(Eu)

The scintillating crystals and plastic scintillators, substrates, scintillation detectors and arrays are provided, a variety module of the NaI(Tl) crystals and detectors, high quality arrays of LYSO(Ce), CsI(Tl) or CdWO4 are offered. Our scintillating materials include: LYSO(Ce), YSO(Ce), LSO, BGO, YAP(Ce), YAG(Ce), LuAG(Ce), CsI(Na), NaI(Tl), CsI(Tl), CaF2(Eu), BaF2 and plastic scintillators. These products are widely used in X-ray detections, PET machines, atomic and nuclear ray and electron ray detections, cut and polished components and arrays and PMT assembly detectors are available for your applications.

Caf2(eu) scintillator as a efficient scintillation crystal, has been widely used in the application of low energy nuclear physics experiment, nuclear reactor detecting, radiation monitor and radioactivity medical science diagnoses.

Features

  • Relatively high light output
  • Inert
  • High shock resistance

Specifications

Growth method: Bridgman

Maximum dimension: ∅60 mm x 120 mm

Available items: single crystal

Basic Properties

 Note: The crystal boules, blanks and polished elements are available.

Application Notes

  • P-Detector
  • Radioactivity medical science diagnoses

 

 

 

Relevant Aspects for the Choice of Nonlinear Crystals

Many different properties of a nonlinear crystal can be important for an application e.g. in nonlinear frequency conversion:

The chromatic dispersion and birefringence properties determine the possibilities for phase matching and the phase-matching bandwidth, angular acceptance (for critical phase matching), etc.
The magnitude of the effective nonlinear coefficient deff, which depends on the nonlinear tensor components and on the phase-matching configuration, is important particularly if the achievable optical intensities are low.
Normally, the crystal material should have a high optical transparency for all wavelengths involved.

Additional properties can be relevant for a comparison:

the material’s potential to be periodically poled to achieve quasi-phase matching
linear absorption, which can cause heating at high optical power levels, so that the phase matching is disturbed, and thermal lensing may occur
the resistance against optical damage, gray tracking, photodarkening, green-induced infrared absorption, and the like
the resistance against photorefractive effects (which are often called photorefractive damage, even though this is usually reversible)
the availability of crystals with consistently good quality, large size and a reasonable price
the ease of fabricating high-quality anti-reflection coatings on the crystals
the chemical durability; e.g., some crystal materials are hygroscopic, others undergo chemical changes when heated in a vacuum chamber for application of a dielectric coating
The choice of the most suitable crystal material for a given application is often far from trivial; it should involve the consideration of many aspects. For example, a high nonlinearity for frequency conversion of ultrashort pulses does not help if the interaction length is strongly limited by a large group velocity mismatch and the low damage threshold limits the applicable optical intensities. Also, it can be highly desirable to use a crystal material which can be critically phase-matched at room temperature, because noncritical phase matching often involves the operation of the crystal in a temperature-stabilized crystal oven.

Far Infrared Dome

There are many far infrared (FIR) units on the market which is very confusing to the public. This page will explain how they came into existence and the differences between them. This is important so as not to spend a lot of money on something that will not give optimal far infrared benefits as expected and desired, especially if intended for specific use as thermal therapy.

The unit is called the Far Infrared Dome. The traditional sauna companies took note of this far infrared ‘dry’ sauna and shortly thereafter followed suit by incorporating far infrared heat into their existing set-up.

Source of Far Infrared Rays and the difference between wet and dry heat:
Traditional saunas introduced carbon coated metal rods or carbon coated ceramic plates into their existing sauna units to generate far infrared heat and then renamed and marketed them as far infrared sauna even though they still remain a traditional sauna generating a hot ‘wet’ heat.

A traditional sauna uses heat to warm the air, which in turn heats up your body. This is a ‘wet’ heat which therefore requires you to remove your clothes.

A far infrared sauna heats your body directly, without warming the air around you. Far Infrared is a ‘dry’ heat, clothing is optional. There is no sweating involved – toxins are released through the urine and feces.

None of the traditional ‘infrared sauna’ (or the copycat far infrared sauna domes) use the same advanced unique patented crystal chip surface as the Far Infrared Dome which emits 100% pure far infrared. Most far infrared saunas emit 40% to around 90% far infrared (very few units reach 90%). Some far infrared sauna units generate too much wet heat and thereby dramatically reduce the actual far infrared emission level.