Spectrometry with your microscope!
Optical microscopes are routinely found in a wide variety of laboratories, but they are often only used as a magnifying glass to allow the user to better see the sample. However, even an inexpensive microscope can be upgraded to do so much more! By sending the light from the microscope to a spectrometer, many different types of spectra can be measured with a much smaller sampling area than is capable with a standard bench-top spectroscopy tool, such as transmission, reflection, fluorescence, and other types of optical emission. Microscope spectrometry, using microspectrophotometers (MSP), measures UV-VIS-NIR spectra of microscopic samples or microscopic areas of larger objects. While a standard spectrophotometer is designed to measure samples on the order of 1 x 1 centimeters, the microspectrophotometer is able to measure samples on the order of 1 x 1 micrometers...much smaller than the thickness of a human hair. The 508 PVTM microscope spectrophotometer is a modular head unit that can be installed on the open phototube port of most upright microscopes to add spectroscopy to your microscope. With CRAIC Technologies products, you can acquire high quality spectra of even sub-micron samples rapidly, non-destructively and with ease.
As shown in the diagram on the right, the MSP head unit can be added to the photoport of a microscope, and the spectrometer measures the light that is collected by the objective and focused onto the spectrophotometer entrance aperture. Whether this light is transmitted through the sample, reflected from the sample, or emitted by the sample, that only changes the calculations done on the light intensity measured.
Beyond just measuring UV-VIS-NIR spectra with microscale sampling areas, microscope spectrometry is also capable of microspot thin film thickness and colorimetry measurements. When combined with motorized stages, hyperspectral data cubes can even be created with various types of spectra. Because these instruments are so flexible, MSP's are used in many diverse fields of research and industry.
As shown in the diagram on the right, the MSP head unit can be added to the photoport of a microscope, and the spectrometer measures the light that is collected by the objective and focused onto the spectrophotometer entrance aperture. Whether this light is transmitted through the sample, reflected from the sample, or emitted by the sample, that only changes the calculations done on the light intensity measured.
Beyond just measuring UV-VIS-NIR spectra with microscale sampling areas, microscope spectrometry is also capable of microspot thin film thickness and colorimetry measurements. When combined with motorized stages, hyperspectral data cubes can even be created with various types of spectra. Because these instruments are so flexible, MSP's are used in many diverse fields of research and industry.
Relative Intensity Measurements of Displays
Figure 1: Microspectrometers are used to measure the intensity of each pixel
Figure 2: Typical test spectra from a display. Intensities can be directly compared between pixels.
The luminance, intensities or brightness of individual pixels and groups of pixels can be measured and compared using microspectrometers.
Flat panel displays consist of a series of colored lighted areas arranged in a pattern and can only be readily viewed with magnifying optics. Due to the high resolution of flat panel displays, they are manufactured with hundreds of rows of microscopic "pixels" on a surface. Generally, these pixels are red, blue and green though pixels with other colors are also made...for example the latest four color systems also incorporate yellow pixels.
One aspect of display quality control consists of making sure that the brightness or intensity of each pixel does not vary across the entire display. For example, all the green pixels should have the same brightness no matter where they are positioned in the display.
Microspectrometers are able to gather relative intensity data from single pixels and from groups of pixels (if you are interested in mura). Additionally, microspectrometers are also able to map the relative intensity variation within even a single pixel! This leads to a new level of precision for improved displays.
The way a microspectrometer works is that spectrophotometer entrance aperture is placed over the pixel or pixels in questions. The black square in Figure 1 is an example. The spectra is then acquired and will look something like the three spectra in Figure 2. Using the LambdaFire™ software, the intensity data is compared with measurements of other pixels to show that the brightness of each sampled area is within the manufacturing parameters. A high resolution map of the relative intensities can then be generated.
Learn more about relative intensity measurements of displays below:
Microdisplay Inspection
Typical test spectra from a microdisplay
Microdisplay Inspection: Color, relative intensity, spectroscopy and film thickness of pixels and light sources.
Microdisplays consist of a series of colored lighted areas arranged in a pattern and can only be readily viewed with magnifying optics. They are used as high resolution displays for everything from mobile phones to video display headgear to MP3 players. There are many different designs but their small scale causes many quality control challenges.
Due to the nature of microdisplays, they are manufactured with hundreds of rows of microscopic "pixels" on a surface. These pixels can be smaller than 10 microns across. Quality control of both the components and completed microdisplays is done by optical microspectroscopy. Microspectrometers, such as those made by CRAIC Technologies, are used to measure the color and the intensity of the output from individual pixels and from groups of pixels. In fact, CRAIC microspectrometers can be used to map the color and intensity outputs of individual pixels in addition to the entire microdisplay. This is important as manufacturers of microdisplays need to make sure that all the different types of pixels are the same color and brightness. A microspectrophotometer does this quickly and easily.
To learn more about microdisplay testing:
What is a Microspectrophotometer?
SWIR Microscopy
SWIR Microscopy is microscopy for imaging in the shortwave infrared region.
SWIR microscopes are designed to "see" beyond what a standard optical microscope can image. With special SWIR optics, light sources and cameras, SWIR microscopy is for imaging microscopic samples in the visible and the shortwave infrared region. This means that SWIR microscopes have features that make them superior to normal visible range microscopes:
- Some materials are transparent in the SWIR while being opaque in the visible region
- Enhanced contrast of certain materials in the SWIR region.
For example, silicon is opaque under normal light but is transparent in the SWIR region. The interiors of silicon based devices can therefore be inspected without having to disassemble them.
CRAIC Technologies offers a number of solutions for the shortwave infrared microscope. These custom designed microscopes capable of imaging from the visible region all the way into the shortwave infrared. They are capable of microscopy in transmission, reflectance and even fluorescence.
Learn more about SWIR microscopy:
SWIR Microscope
The SWIR Microscope is a microscope that images in the SWIR region.
SWIR microscopes are designed to "see" beyond what a standard optical microscope can image. With special SWIR optics, light sources and cameras, SWIR microscopes can image microscopic samples in the visible and the shortwave infrared region. This means that SWIR microscopes have features that make them superior to normal visible range microscopes:
- Some materials are transparent in the SWIR while being opaque in the visible region
- Enhanced contrast of certain materials in the SWIR region.
For example, silicon is opaque under normal light but is transparent in the SWIR region. The interiors of silicon based devices can therefore be inspected without having to disassemble them.
CRAIC Technologies offers a number of solutions for the shortwave infrared microscope. These custom designed microscopes capable of imaging from the visible region all the way into the shortwave infrared. They are capable of microscopy in transmission, reflectance and even fluorescence.
Learn more about SWIR microscopes:
