November 2019

Specialized Microscope Configurations in China

One of the unique advantages of the WITec alpha300 confocal microscope series is its modularity. Customers can configure systems to meet the specific requirements of their research, and even reconfigure them as their experiments evolve. This flexibility combined with the components' inherent stability also allows integration with many other laboratory devices, such as environmental enclosures and sample stages.

WITec Product Manager Dr. Tom Dieing recently traveled through China and met with groups operating specialized WITec microscopes that show how alpha300 series modules can be assembled to create the perfect tool for a particular job.

At Fudan University – Shanghai Institute of Intelligent Electronics and Systems, a system based on the alpha300 R was modified to investigate heterostructures of graphene and tungsten disulfide. It allows high resolution confocal Raman imaging measurements ranging from <8K up to 500K inside a cryogenic cell that is fully integrated onto the alpha300 R motorized stage. It also features three excitation lasers in 532, 633 and 785 nanometers with full polarization control for the analysis of temperature- and polarization state-dependent Raman and photoluminescence signals.

Fudan University – Laboratory of Advanced Materials configured an instrument for research on black phosphorus and high temperature superconducting materials that uses an alpha300 R located within a sealed Argon-filled glove box. This allows samples produced with molecular beam epitaxy (MBE) or chemical vapor deposition (CVD) to be brought directly onto the microscope stage without exposing them to air. The small footprint and fiber-based excitation and detection paths integral to all WITec microscopes enable the electronics, lasers and spectrometer to be placed directly under the enclosure. This instrument also includes the remotely-operated TrueComfort option for automated white light/Raman switching and TruePower for precise, repeatable laser power determination.

At the Department of Modern Optics at Nanjing University there is a 488nm laser for Raman and PL measurements, a current-sensing module and a 1064nm picosecond pulsed laser set up for second harmonic generation (SHG) experiments. The group performs correlative investigations of 2D materials that they produce themselves, including MoS2.

The Laboratory of Advanced Nanomaterials at Wuhan University has an alpha300 RA Raman/Atomic Force Microscopy system with a 488nm laser, a UHTS300 spectrometer with an EMCCD for detection, a super continuum white light source for photocurrent and photoluminescence measurements and a temperature stage with a range of -196C to +1000C. This stage allows the researchers to recreate the conditions of chemical vapor deposition (CVD) growth for optimal multimodal imaging and characterization of 2D materials.

The School of Materials Science and Engineering at Huazhong University of Science and Technology (HUST) operates an alpha300 RAS featuring detection from 350nm to 1700nm with three UHTS spectrometers. The setup is optimized for experiments that employ Raman microscopy, photoluminescence, scanning near-field optical microscopy (SNOM), second harmonic generation (SHG) and time correlated single photon counting (TCSPC) methods such as fluorescence lifetime imaging (FLIM). With their primary focus on 2D materials, the group produced almost 20 peer-reviewed publications in 2018 alone using this versatile and modular instrument.

These examples offer only a glimpse into the range of configurations possible with the alpha300 series. The WITec sales team is ready to discuss your individual requirements and to start configuring the system that is right for you.

An alpha300 RA Raman/Atomic Force Microscopy system for second and third harmonic generation (SHG and THG) investigations of MoS2 at the same position using a 1560nm picosecond pulsed and a temperature stage with a range of -196C to +1000C .