EUCLID DELIVERS A BRAND NEW TECHNOLOGY: AN ULTRAFAST GHZ ELECTRON BEAM PULSER TO CONVERT A CONVENTIONAL TEM INTO A POWERFUL, TIME-RESOLVED ULTRAFAST ELECTRON MICROSCOPE.
As an addition to the family of time-resolved electron probe methods, Euclid’s GHz stroboscopic pulser addresses a different temporal landscape that is complementary to existing commercial solutions. Unlike many recent UTEM developments that rely on a sophisticated and expensive pump-probe fs laser system, Euclid’s technology is a laser-free set-up. It reduces the price tag and operational cost of the whole UTEM system significantly, providing essential relief for electron microscopists who are not familiar with laser systems. We can retrofit old TEMs or pre-install our product in brand new TEMs. Sample holder customization for RF pump-probe is available. Read the DOE SBIR Success Story on our technology.
Euclid’s innovation is to use RF cavity resonator technology to manipulate the TEM electron beam. In this way, the physics and methods widely adopted in electron beam accelerators are employed to produce a fundamentally different stroboscopic instrument, which can be built on any TEM platform, because the electron emission process is unchanged. Euclid’s patented technology consists of a series of magnetic quadrupoles and stripline resonators, which surpass deflecting cavities in achieving ultra-broad tunability. This apparatus modulates and chops the incoming dc electron beam and converts it into pico- and sub-picosecond (100 fs to 10 ps) electron pulses with maximum repetition rates above 10 GHz. The resulting bunches do not experience phase-space degradation compared to the incoming dc beam, requiring no change in the complex electron optics that makes up the core of a TEM. The basic principle of Euclid’s GHz stroboscopic TEM is presented in the Figure below.
Comparison with laser-based UEM systems
There are four significant factors making our product a unique enabling technology for transmission electron microscopy and its quantitative methods to measure dynamic properties of materials and devices in situ and in operando:
HIGH PULSE REPETITION RATE (UP TO 20 GHZ) OUTPERFORMS LASER TECHNOLOGIES
All laser-based stroboscopic UTEMs generally do not operate at frequencies higher than 0.1 GHz (typically at ~0.1 MHz) due to laser recharge limitations and heat deposition in the specimens. On the other hand, our laser-free system can benefit from a phase-locked RF drive to provide pump and probe with substantially higher repetition rate and beam current than the presently available stroboscopic UTEM.
TUNABILITY AND LARGE DUTY CYCLE ANOTHER IMPORTANT PARAMETER IS BEAM DUTY CYCLE IN ELECTRON OR PHOTON PULSE SEQUENCES.
At the moment, the aforementioned laser-based tools yield a very small <10^-5 duty cycle with very limited tunability. The uniqueness of Euclid’s electron pulser is its flexibility to vary the electrons per pulse and pulse rate independently with a high duty cycle up to ~10%. Therefore, GHz stroboscopic laser-free TEM, enabled by Euclid’s electron beam buncher, has an immediate advantage in terms of the amount of time required to accumulate a measured signal at much higher time-averaged probe current. The short time required per experiment and high throughput is the crucial link to industrial needs because it has the potential to boost reliability, repeatability, and failure analysis in device R&D, lab-to-fab translation, and large-scale/mass production.
LASER-FREE AFFORDABLE SOLUTION FS LASER-BASED UEM CAPABILITY HAS A VERY HIGH PRICE TAG.
The necessity to both own and operate a non-standard electron microscope and an ultrafast laser system limits the technology to only a few research groups in the world. Euclid’s technology replaces the expensive and sophisticated fs-laser system with a relatively inexpensive electromagnetic-mechanical pulser that significantly reduces the price for a UEM system. Eliminating the need for a laser is expected to be also a significant relief in terms of safety precautions and maintenance budget for a lab.
RETROFITTABLE SOLUTION LASER-BASED UEM SYSTEMS ARE COMPLEX ASSEMBLIES WHICH MODIFY THE TEM SYSTEM SIGNIFICANTLY.
Another competitive advantage of our electron buncher technology is in its compatibility with commercial TEM platforms: retrofitting it into the TEM is less invasive. We can retrofit old TEMs or pre-install our product as an option in brand new TEMs. Upon introducing a GHz pulser assembly into the high voltage section of such TEM, the modified system can work in two distinctly different modes: (1) the standard high spatial resolution imaging mode, and (2) a high spatio-temporal resolution mode with space-time resolution <10-20 m·s.
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