B&W Tek, Inc. - Econic

#1 SMA

B&W Tek, Inc. offers a standard SMA adaptor used with the coupling of fiber optics or lenses which will aim light into the spectrometer’s optical bench. Coupling a fiber or lens to the SMA 905 adaptor, light will be precisely aligned and focused onto the slit and optically matched for maximum light collection inside the spectrometer’s optical bench.

B&W Tek, Inc. offers an optional innovative “keyed” SMA adaptor which ensures unmatched reproducibility.

For more information on our “keyed” SMA connector click here.

Coupling:
B&W Tek, Inc. recognizes that sometimes you need a connection other than the industry standard, SMA 905. If your coupling needs for your SMA Plate or Fiber ends require an alternative we offer adaptor upgrades ranging from SMA to ST or SMA to FC.

Please contact our Application Team for more input options.

Note about matching the input fiber NA to the Spectrometer.

#2 Custom Pre-Mounted Slits Back to top

The slit of a spectrometer ultimately determines the optical resolution and throughput of the spectrometer.

Light entering the optical bench of a spectrometer via a fiber or lens is focused onto the pre-mounted and aligned slit.

We offer a variety of slit widths to match your specific application needs from as small as 5µm to as large as 800µm, with a 1mm (standard) to 2mm in height. It is important to select the correct slit since they are aligned and permanently mounted at our facility and can not be replaced in the field.

The spectrometer is an imaging system which maps a plurality of monochromatic images of the entrance slit onto the detector plane. This slit is critical to the spectrometer’s performance and determines the amount of light (photon flux) that enters the optical bench and is a driving force when determining the spectral resolution. Other factors are Photon flux, Grating Grove Frequency and Detector Pixel size.

Refer to the chart below for selecting which slit is right for you.

Slit Size	Resolution
10	<= 0.8nm
25	<= 1.5nm
50	<= 2.5nm
100	<= 6.0nm
200	<= 10.0nm

Still not sure what slit you need? Contact our Applications Team for help choosing the correct slit for your application.

For more technical information on the entrance slit click here.

#3 Collimating Mirror Back to top

Collimating (Mirror 1) the light from the Entrance Slit allows the surface of the grating to be completely filled, ensuring maximum light dispersion or diffraction off the grating which is then reflected at specific angles to be collected by the Focusing Mirror (Mirror 2).

The Collimating Mirror (Mirror 1) is coated with AlMg2 which produces around 95% reflectance when working in the UV-Vis spectrum. Al is for the reflectance and Mg2 protects the Al from oxidization. This coating is standard with every system. When working in the NIR spectrum we offer other coatings for NIR enhancement.

Please contact our Applications Team for further information on Collimating Mirror enhancement coatings.

#4 Wavelength Coverage & Resolution Back to top

The grating will determine the wavelength range and has a part when determining the optical resolution that the spectrometer will achieve.

Using the correct grating is key to optimizing your spectrometer for the best spectral results in your application. Grating will influence your Optical Resolution and the Maximum Efficiency for a specific wavelength range.

Grating can be described in two parts: Groove & Blaze

Groove:
Resolution (the amount of dispersion) is determined by the amount of groves per mm ruled into the Grating. This is commonly referred to as Groove Frequency, or Groove Density. Groove Density will determine Wavelength Coverage and Resolution which are inversely related.

For example a 1200g/mm will give you wavelength coverage of 270 nm at a time, with an optical resolution of 0.3nm. 600g/mm will give you 650nm of coverage at a time with an optical resolution of 0.6nm. You can increase your Wavelength Coverage at the sacrifice of Optical Resolution.

Blaze:
Will determine the maximum efficiency the grating will have in respect to a specific wavelength area.

Blaze Angle or Blaze Wavelength of the grating will determine the maximum efficiency that the grating will have in respect to a specific wavelength area. We offer two standard Gratings for the Econic (see chart below) and an assortment of upgradable Gratings to match your application needs if required.

It is important to select the correct grating since they are aligned and permanently fastened into place at our facility and can not be replaced in the field.

The charts below show the Grating Efficiencies of the two standard gratings you can select from when building your Econic spectrometer. If you don't see exactly what you need or have any questions, please contact our Applications team.

For more Technical information about gratings click here.

#5 Focusing Mirror Back to top

After being dispersed by the Grating, the Focusing Mirror (Mirror 2) collects all of the light at the specific angles of incident from the grating and refocuses the individual wavelengths across the focal plane of the detector.

The Focusing Mirror (Mirror 2) is done with AlMg2 which produces around 95% reflectance when working in the UV-Vis spectrum. Al is for the reflectance and Mg2 protects the Al from oxidization. This coating is standard with every system. When working in the NIR spectrum we offer other coatings for NIR enhancement.

Please contact our Application Scientists for further information on Focusing Mirror enhancement coatings.

#6a Filter Back to top

A Linear Variable Filter (LVF) is designed to block 2nd order wavelengths from hitting the detector. An LVF is needed when a unit’s set range has its highest set wavelength being greater than two times that of its lowest set wavelength. For example, a 350nm – 1050nm Econic will require an LVF while a 200nm – 400nm Econic will not.

#6b The Detector

The Econic features a non-cooled 2000 element linear silicon CCD array detector with a pixel format of 2000 x 1 elements @ 14µm per element. Effective (Active) pixels > 1950.

How the Detector works:
As the incident light strikes the individual pixels across the CCD each pixel represents a portion of the spectrum that the electronics can then translate and display with a given intensity using our software, BWSpec™.

The quantum efficiency (QE), dynamic range (DR) and noise level of array detectors largely dictate the spectrometer sensitivity, dynamic range and signal-to-noise ratio. The spectral acquisition speed of the spectrometer is mainly determined by the detector response over a wavelength region.

#7 Cooling the Detector Back to top

The Econic does not come with a Thermoelectrically Cooled (TEC) detector. Adding this feature would require purchasing a different spectrometer model entirely.

Our Compass™ spectrometer features 2048 element linear silicon CCD array detector with a pixel format of 2048 x 1 elements @ 14µm x 200µm per element.

A cooled detector will reduce noise level, therefore increasing signal-to-noise ratio.

The longer the exposure time (integration time) the higher the noise from the detector. Cooling your detector will reduce this noise significantly when compared to non-cooled versions of the same detector type.

You will need TE Cooling if:

Light Starved Application
Long Exposure Times
Detection of Small Changes in Signal Levels
High Dynamic Range
Reproducibility from Spectra-to-Spectra

You do not need TE Cooling if:

Strong Light Application
Short Exposure Times
Prefer a Low Cost Spectrometer
Do not need to discriminate between small changes in signal from spectra to spectra

More on TEC

In order to make any detector photosensitive there needs to be a voltage applied. Inherently a small output is detected with our scientific grade detectors, even when no light is present. This is known as the dark current or dark output. Dark current is caused by thermally generated electron movements and is strongly dependent on ambient temperatures of the detector.

For silicon detectors (UV–NIR), dark current halves for every 5-7°C decrease in temperature and doubles when the temperature increase every 5-7°C.

For More information on cooling click here.

#8 PC Interface

The Econic comes with USB 2.0/1.1 Plug-and-play capabilities. The necessary USB Cable is included with your order.

Your PC must have an Operating System of Windows XP or higher, 5GB of available hard drive space, 512MB of RAM and a USB Port.