Scanning Electron Microscope Cathodoluminescence
The SPARC cathodoluminescence system for nanophotonic measurements


SEM Cathodoluminescence - Delmic Correlative Microscopy- SPARC system - Nanophotonic Measurements with CL
Local Optical Density of States - Angle Resolved Measurements - Nanomaterial Characterization - SPARC Features


Scanning Electron Microscope Cathodoluminescence (SEM CL)
Cathodoluminescence is an optical phenomenon that occurs when an electron beam impacts a surface and generates light emission. The collected light is detected and can be used to generate images and spectra for analysis. Scanning electron microscope (SEM) cathodoluminescence has traditionally been used in geology and material science to analyze rocks, ceramics, and semiconductors to obtain information on the chemical composition, growth or quality of the material. DELMIC manufactures cathodoluminescence systems that go beyond the traditional applications, providing the unique capability to perform new types of optical experiments with SEM CL.

Correlative Light image of this sampleSEM image of this sample
       Correlating CL and SEM images of the same sample.

SPARC System - Cathodoluminescence Designed for Nanophotonics
The SPARC is a cathodoluminescence imaging system for the study of micro and nano photonic structures. The system allows for new types of experiments in nanophotonics. Maximum collection efficiency is ensured through the precise alignment of the mirror with respect to the electron beam. The system is designed with motorized stages that allow the mirror to be positioned in X, Y, pitch and Yaw. The combination of the precision aligned mirror with top-of-the-line detectors, offers unsurpassed sensitivity, control and versatility. This makes it possible to easily and reliably probe structures with very low photon yield, making ideal for the investigation of nano antennas, wave-guides, semiconductors devices and photonics crystals

Nanophotonic measurements with Cathodoluminescence
The field of nanophotonics is rapidly growing in research and industry. In nanophotonics, one must be able to measure and characterize subwavelenght light from devices such as nano-antennas, waveguides and photonics crystals.  Traditionally, near-field scanning optical microscopes (NSOM) or tipped enhanced Raman spectroscopy with AFM (TERS) has been used, but these methods are very slow, unreliable and unrepeatable. The DELMIC SPARC system with an SEM offers a solution to the difficulties encountered by NSOM and AFM/TERS. A scanning electron microscope’s tightly focused electron beam effectively behaves like a radiating dipole source at the electron impact position. The electric field generated by the electron beam excites the photonic modes and resonances of a photonic nano- and micro-structures over a spectral range spanning the entire UV/VIS/near-IR spectral range. Scanning electron microscopes make it possible to focus the electron beam to spot size smaller than 10 nm, enabling optical spectroscopy and imaging at a resolution 50-100 times smaller than the optical wavelength. 

Measuring Local Optical Density of States
The collected light is spectrally analyzed for every electron beam position, creating a two-dimensional emission map. This map is a direct measure of the local optical density of states. The local optical density of states can be measured with a spatial resolution of 10-30 nm.

Angle Resolved Measurements
The SPARC system is equipped with an imaging CCD that records the beam profile emitted from the mirror. The profile is used to derive the angle-resolved pattern, enabling momentum spectroscopy, measuring the in-plane vector of light at every frequency and position. With this technique you can determine the local bandstructure of periodic and aperiodic structures with a spatial resolution of 10-30 nm.

Directional emission and 2D CL map of an optical antenna
Directional emission and 2D CL map of an optical antenna
Directional emission and 2D CL map of an optical antenna
     Directional emission and 2D CL map of an optical antenna Composed of five 100nm Au particles
     Images are courtesy of the Polman group, AMOLF

 

Nanomaterial Characterization with Cathodoluminescence
In nanomaterial characterization, the electron beam may be used to locally probe nanostructures. The resulting cathodoluminescence spectrum can give information on material type, purity and defects.  The SPARC system enables high collection and detection efficiencies, making it possible to investigate structures with low photon yield.


DELMIC SPARC Cathodoluminescence System Features

DELMIC Correlative Light and Electron Microscopy Solutions
Nanounity is a distributor for DELMIC. DELMIC is a manufacturer of correlative microscopy products for use with SEM, FIB and dual beam systems. DELMIC manufactures SPARC a cathodoluminescence system for nanophotonics, and SECOM for the correlation of fluorescence and electron microscopy.

Contact:
Please contact Nanounity for more information on the SPARC product and correlative microscopy solutions at info@nanounity.com or feel free to call us at (408) 235-8888.