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Customer Testimonials
"Really solving the problem of an industry such as pharmaceutical or any others is not just buying blackboxes or NIR analyzers, that is very minor part. The biggest solution or bigger problem is how we make that work on a daily basis in a plant. That is what I found it to be particularlly useful with Brimrose."
- Dr. Ali Afnan
Technology Specialist
Technology Specialist
Frequently Asked Questions
Brimrose offers reliable answers to frequently asked questions about general information, products, service, software and hardware. Click on a subject heading below to view questions and answers relating to your selection. Links in the answers will guide you to further information on our website or from other sources. If you have a problem or question not answered on this page, please contact us at office@brimrose.com.Answers and Solutions
How can I view Flash based content with IE9 running on 64-bit Windows 7? Question Catagory In reference to the problem you have with viewing of our website, please check if you install an adequate Flash Player on IE9, 64-bit. If you have an inadquate Flash Player on IE9, 64-bit, it is time to install the new 64-bit version of Adobe Flash. When you upgrade the 64-bit version of Adobe Flash, you might see the message saying the version you want to download isn’t available for IE 9 (64-bit). You can download a preview release from Adobe Labs that is optimized for 32 and 64-bit versions of IE 9. Follow the instruction to download and install Active-X 64-bit for Windows – IE only. Then, you need to download and install the plug-in for 64-bit Windows – for all other browsers too. Now that both have been installed, re-launch IE 9 Beta 64-bit, and you’ll now be able to play Flash Content. Also, we are switching our website to combine HTML5/Flash player setups that maximizes the use of HTML5 Video in the latest browsers while providing full support for legacy browsers with integrated fallback to Flash. Now, audiences can watch Flash content in any browsers and on many popular mobile devices such as iPhone and iPad that do not support the Adobe Flash Player. |
What is 'Acousto-Optics'?
Question Catagory Acousto-Optics (AO) is using the phase grating set up by sound waves inside a material to affect a light beam passing through the material. The sound wave is created by a piezeo-electric transducer bonded to the material (think: ‘joy buzzer.’). The transducer is excited by a RF source. |
What is an Acousto-Optic Tunable Filter(AOTF)?
Question Catagory An AOTF is a device, where putting a mixture of wavelengths into it, one wavelength can be separated (diffracted) out by electronic means. To clarify, except for minor transmission losses, all the light input into one side will be output to the other side; However, the chosen wavelength will be output at an angle different from that of the rest of the light. By means of an aperture, the ‘rest of the light’ (Zero Order) can be blocked, and the chosen wavelength will be the only light emitted. All the ‘chosen light’ (diffracted order, First Order) will be output at roughly the same angle. The ‘electronic means’ is a source of a specific RF frequency for a specific wavelength. The aperture, wavelength range, spectral resolution, and other possible desirata of a given AOTF depend on the details of its construction, and to some degree can be selected. |
What is the difference between AO modulator and AO frequency shifter?
Question Catagory A Modulator is used to change the amplitude of the light signal passing through it. A Frequency Shifter gives a ‘Doppler Shift’ to the frequency of the beam passing through it. That said, a Modulator also gives the signal a small frequency shift, unless a No Frequency Shift model is purchased. Similarly, the amplitude to a Frequency Shifter can often be varied to amplitude modulate the beam passing through it. So to some extent they are interchangeable. |
What is the carrier frequency, and why should I care about it?
Question Catagory The carrier frequency (reading the model number left to right, generally the first number in the model number,) is the frequency shift given to the light beam. The frequency of light is so high (~ 10**15 Hz) that the shift imparted ( ~ 10**8 Hz) is generally negligible. It is the frequency of the grating the acoustics creates in the crystal. |
Why do I care about the carrier frequency of the Modulator I buy?
Question Catagory Modulating is creating and collapsing the sound grating in the crystal; this must be done fast enough to support the modulation rates you want to achieve. In terms of specifications, the carrier frequency should be approximately four times the digital modulation bandwidth; the RF bandwidth quoted should be twice the digital modulation rate wanted, and the RF bandwidth should be approximately four times the analog bandwidth wanted. In terms of functional devices, the smaller the active aperture/beam size, the higher the modulation rates possible. |
What is the Bragg angle, and why is it important?
Question Catagory Except for Acousto-Optic Tunable Filters, the incoming light beam needs to be at the Bragg Angle for the light-acoustic interaction to occur in the crystal. The Bragg angle should be specified in the manual or can be calculated from: sin (Bragg angle) = (Wavelength x Frequency)/(2 x Acoustic velocity in crystal). You can set the device at the Bragg angle and then try translating, but generally the angle is small and set up imprecise, so the empirical way to do it is to put a slow (to the eye, 3 Hz works well) modulation on the carrier frequency, and watch for a blinking spot as the device is slowly rotated around the Bragg angle. The blinking is the First Order (diffracted spot) appearing, or the Zero Order dimming as energy is taken from it to the First Order. Once the angle is found at which the blinking occurs, (the ‘Bragg angle’,) the alignment can be optimized up/down, in/out/ and around. |
The intensity of the diffracted order decreases if the AO device is rotated or moved up, down, in, or out; how else may alignment be off?
Question Catagory The light beam inside the device should be parallel to the electrode to feel the full affect of the acoustic beam. Except in Brewster Cut devices, the electrode is in a normal (perpendicular) direction to the optical faces. Thus to start aligning, the incoming beam should retro-reflect from the front optical. If you have a sensitive source, you may not want the retro-reflection back into a source that could cause run away gain and burn out your source; if this is the case, have the reflection from the AO device to reflect to the side of the source. By the way, acousto-optics is by and large reversible, and it doesn’t matter which side of the AO device is ‘In’ and which side is used as ‘Out.’ You may see 2 retro-reflected spots, one from the front face and one from the back face; the faces are not parallel so the device can not act as an etalon. |
Can I make copies of the products and application forms?
Question Catagory You may not make copies of all products and application forms, which are available only on the Brimrose website. The only way that all the forms can work is when a form handler script that provided by Yahoo web hosting will interpret the form information you place on the form and pass it along to an appropriate destination. These online forms enable our office to process your application faster and more efficiently. |
I want the fastest, largest aperture, most efficient device you sell. What is it?
Question Catagory It is a compromise, as is most of life. The rise time depends on how fast the sound beam crosses the size of the light beam; so using larger light beams will mean slower devices; and generally, the faster acoustic speeds are in lesser efficient materials. In addition, faster devices use higher sound frequencies which attenuate faster in materials. So, details Please? Tell us what you want to do, and we can probably figure out a way to do it. Almost everything we do is custom made, to some extent. |
Why can’t I find any diffraction orders from the free space device I bought?
Question Catagory Well, it could be many things, but usually the problem is in alignment. The light beam needs to intersect the acoustic beam. The acoustic beam height is the ‘Active Aperture’ usually found in the manual. It is smaller than the window size in the case cover to allow for focusing and for the angles involved. Thus, the device may need to be translated in the direction across the acoustic beam. You can not see the acoustic beam, but it is emitted from the transducer, which is generally the side that the “Brimrose” label is on. Especially in higher frequency devices, you may need to translate the device so the light beam is closer to the transducer. The acoustic beam does attenuate as it travels in the crystal, so the strongest acoustic beam is nearest the transducer. Again, the transducer side is generally the side nearest the “Brimrose” label. |
I can’t get any diffraction, and when I put my Ohmmeter across the connector, it shows a ‘short’/’open;’ doesn’t that mean the device is broken?
Question Catagory Not necessarily. The Ohmmeter is meant to work with DC voltages; AO devices work at frequencies generally in the MHz or higher frequencies. Inside the AO device is a circuit that enables the RF power supplied to better excite the transducer; in the circuit may be inductors that show ‘short’ at low frequencies, and capacitors that show ‘open’ at low frequencies. The resistance/impedance is frequency dependent, and requires a RF Vector- or Scalar- Network Analyzer to measure. |
How to create a new user.par if the file is lockout in Windows7? Question Catagory The user.par file located in C:\Program Files\Brimrose\..\ is not used normally by the program. It will create and access a copy of it in a hidden folder. If a lockout occurs and a new */par file needs to be created, please follow the instructions below: 1. go to the Snap32! directory and make a new folder called userpar. 2. paste a new working copy of user.par into this folder. 3. delete all other *.par files from the Snap32! directory. 4. go to C:\Users\Test\AppData\Local\VirtualStore\Program Files\Snap32! and locate the user.par file in the folder. Note: AppData is a hidden folder so you will have to manually search for it in the explorer. 5. delete this file and paste another copy of the working user.par file into this directory. 6. run a Snap32! application. All accounts should now be reset to whatever is on the new user.par file. |
