The industry-oriented research at CAPPA is supported by various equipment all housed in the CREATE building located in the MTU Bishopstown campus. These facilities are detailed below and aim at providing photonics-based solutions to companies in a wide range of sectors. Many of these solutions are based around the extensive spectroscopy, imaging and design capabilities available to CAPPA; this section gives a brief description of these.
A spectrometer is used to separate and measure spectral components of a physical phenomenon. It is used to probe a property of light as a function of its portion of the electromagnetic spectrum, typically its wavelength, frequency, or energy. CAPPA is equipped with a wide array of spectrometers that cover a broad range of the electromagnetic spectrum, specifically X-ray to Mid-Infrared. CAPPA houses a wide variety of spectroscopic instrumentation, which is detailed below:
Energy Dispersive Spectroscopy (EDS)
Coupled with a Scanning Electron Microscope (SEM), this technique complements the high-resolution imaging and also aids product and process analysis for a wide variety of samples. An energy dispersive spectrometer can measure the number and energy of the X-rays emitted from a specimen after stimulated emission from an X-Ray source. As the energy of the X-rays is a characteristic of the atomic structure of the element from which they were emitted, this allows the elemental composition of the specimen to be measured. This can be used in a wide variety of applications from the fundamental study of materials to more applied uses such as analysis of coating processes or determining sources of contaminant.
The various UV/Vis/NIR Spectrometers allows for the absorption and reflection measurement of liquid and solid samples using a combination of benchtop instruments (Shimadzu, Andor) or modular spectrometers (Ocean Optics). From UV to NIR, absorbance and reflectance measurements provide valuable information about the chemical composition of materials in all states of matter.
Fluorescence is the absorption and emission of two different wavelengths of light. Typically, a lower wavelength of light is absorbed from one direction, and a higher wavelength of light is emitted in all directions. CAPPA offers a range of fluorescence measurement set up that can provide high sensitivity and quantitative results.
Raman Imaging Spectroscopy
Raman spectroscopy is a widely used technique applicable in the study of Carbons, Nanomaterials, Forensics, Life Sciences, Minerals, Geology and Gems, Pharmaceuticals and Polymers. Raman scattering is based upon the interaction of light with the chemical bonds within the sample. Raman microscopes utilise the combination of imaging and spectroscopy to produce chemical 3-dimensional data cubes, that develops a standard microscopic image into a chemical image. CAPPA has two Raman Confocal Imaging Spectrometer with 532 nm, 633 nm, 785 nm and 830 nm laser lines.
IR Spectroscopy & Imaging take advantage of the functional groups of every molecule that generate characteristic absorption or transmission spectra that definitively identifies that chemical compound. Both Near and Mid-IR images give rich information revealing the identity of a broad range of chemical components in materials, as well as displaying areas of homogeneity and difference. CAPPA possesses three IR spectrometers, two Fourier Transform InfraRed (FT-IR)based systems and a state of the art Quantum cascade laser (QCL) system.
Hyperspectral imaging improves vision and discrimination power by using spectral signature information of surface materials, and it is one of the most promising techniques currently investigated for quality evaluation purposes. The Hyperspectral imaging system at CAPPA, incorporates a spectral camera (HySpex SWIR – 384) with several lenses on a translation stage, combined with a focused broadband illumination source. The camera has a state of the art MCT sensor with cooling down to 150K which yields low background noise, high dynamic range and exceptional signal noise (SNR) levels, making it ideal for a wide range of applications.
Microscope Imaging Facilities
CAPPA employs a wide range of microscope systems covering basic inspection application to high-resolution imaging to aid photonic device understanding and development as well as for product and process analysis for a wide variety of samples
A Scanning Electron Microscope (SEM) is analogous to an optical microscope. However, instead of illuminating the sample with light, it images the sample surface by raster scanning it with a high-energy beam of electrons. The electrons interact with the atoms that make up the sample producing signals that contain information about the sample’s surface topography as well as composition. The system at CAPPA has a large chamber to allow observation of specimens at diameters up to 300mm. The chamber allows for Variable Pressure (VP) which enables observation of non-conductive samples like electronic components, and water containing samples such as cultured cells, without any sample preparation.
Equipped with a range of objectives, filter cubes, polarisers, and bright and dark field illumination CAPPA offers a wide array of imaging facilities for numerous sample types. The microscopy equipment ranges from basic stereo microscopes to confocal systems. These systems find use in routine laboratory work to state of the art research applications.
CAPPA has a variety of light sources to cover a range of industrial application and product development. Light can be employed for a range of custom imaging applications, depending on the task, light intensity and object size, CAPPA can develop bespoke optical solutions from a range of sources. Light sources include simple LEDs to laser and supercontinuum sources. With a wide range of wavelengths available, it is possible to develop bespoke solutions based on lost cost semiconductor technology. Initial development would involve advanced illumination sources to determine the optimum wavelength and later substitute to a low-cost alternative for a prototype design.
Light and optical characterisation Facilities
CAPPA offers a range of equipment to support the characterisation of LEDs, Lasers and broadband light sources. Typical characteristics can include optical intensity profiles and optical power or flux. Determination of aberrations in lens manufacturing can be provided for both industrial mass-produced spherical and aspherical lenses and intraocular lenses. This is achieved through various systems such as beam profiles, wavefront sensor and integrating sphere. All of these systems are managed by the dedicated team of highly trained staff with many years of academic and industrial experience, who can advise on the most appropriate method for testing.
3D printing is a process of making three-dimensional solid objects from a digital file, typically, Computer Aided Design (CAD). The creation of a 3D print is achieved using additive processes. 3D printing enables you to produce complex shapes using less material than traditional manufacturing methods. CAPPA can help develop prototypes with their 3D printing facilities. CAPPA’s 3D printing facilities provide the opportunity to develop rapid prototypes, manufacturing aids, end – use parts and architectural models.