Chengdu Miji Technology Co., Ltd. successfully delivered a set of terahertz near-field optical microscopy system to Henan University of Technology in 2024. The system performs reflective terahertz near-field imaging. The main body of the system is composed of a solid-state source (97.8GHz, 80mW), a detector and a near-field dedicated atomic force main mechanism.
Description of system functions:
The system is a scattering terahertz near-field scanning imaging system containing a scattering near-field optimized AFM, a sample scanner with an XY-axis closed-loop and a Z-axis open-loop scanner, and integrates a parabolic mirror including a three-dimensional electric displacement table for focusing external light sources to the AFM tip. The system is able to efficiently extract near-field signals and suppress background noise: simultaneous signal demodulation for each pixel of the 1st to 3rd harmonic order of the tip frequency that supports 2 independent signals (mechanical/AFM and s-SNOM signals).
terahertz near field imaging:
terahertz near-field microscopy is a technique that utilizes terahertz waves (frequency range approximately 0.1-10 THz, wavelength 30 μm to 3 mm) for high-resolution imaging. Traditional terahertz imaging is limited by optical diffraction limits, and its resolution is generally comparable to wavelength. However, using the tip enhancement effect, THz s-SNOM can break through this limitation and limit the terahertz wave to the volume of the nanoscale to achieve nanoscale super-resolution imaging, while maintaining the unique spectral characteristics of the terahertz band, and at the same time achieve effective enhancement of the weak terahertz signal through surface plasma, tip field enhancement, and resonant structure. This technology has important applications in materials science, biomedicine, physical chemistry and semiconductor testing.
Miji Technology’s terahertz scattering near-field imaging system uses a high signal-to-noise ratio terahertz system to achieve up to 3 orders of near-field imaging while obtaining AFM topography data for the surface of the sample. After actual measurements, the system can achieve nanoscale
While pursuing the quality of near-field imaging, the system also provides users with maximum interaction friendliness in the software: the system operation user interface based on workflow, the interface is simple, and it is easy for researchers or staff who are not familiar with near-field imaging to get started in a short time.
Atomic Force Microscopy (AFM) in near-field systems is an open-ended structure designed for near-field optical applications. Unlike most traditional AFMs on the market, near-field optical AFMs need to have multi-channel demodulation output while maintaining space openness. The open structure is designed to ensure that external light sources, such as visible, infrared, and terahertz waves, can be precisely focused to the tip of the needle. At present, the mainstream near-field AFM equipment on the market is dominated by German brands (such as the Nearspec series and the Bruker IR series), although the performance is excellent, it is expensive, and it is difficult to achieve efficient integration with the customer’s own terahertz equipment. In response to this situation, the near-field AFM developed by our company has designed a variety of types and focal lengths of special-shaped off-axis focusing lenses while maintaining an open structure, which can be more widely adapted to various types of terahertz light sources, significantly improving the compatibility and practicability of the equipment.
Source: Chengdu Miji Technology Co., Ltd. official website View Original