The materials in this article are provided by Teacher Liu Yulong of the Institute of Physics of the Chinese Academy of Sciences, and I sincerely thank Teacher Liu Yulong for his support to Oceanhood!

1.    RMS1000 Instroduction

The RMS1000 (Raman Minimal System) is another small 785nm Raman spectrometer newly developed by Oceanhood. Integrating core components such as lasers, Raman probes, fiber optic spectrometers and photodetectors into a small, high-performance, scientific-grade portable Raman spectrometer. It has excellent performance such as high sensitivity, high signal-to-noise ratio, and wide spectral range.

The whole machine configured with the RMS1000 fiber spectrometer has a small size, light weight, and can be used alone. It can also be used as a handheld, portable, box and other standard Raman spectrometer systems. Products can also be customized to user needs and probes and sample holders are available specifically for inspection needs. It can fully meet the needs of scientific research institutes, relevant regulatory agencies and enterprises in inorganic/organic materials, biological life, chemical/chemical, pharmaceutical analysis, food safety, forensic identification, environmental pollution detection and other research needs.

2. Feature

• Excellent performance: up to the scientific grade spectral performance, with high resolution, high sensitivity, high noise ratio and other  advantages.

• Non-destructive testing: Direct inspection through transparent or translucent packaging, such as glass, plastic bags, etc.

• Long-distance test: can be detected from 1m from the sample.

• Powerful software: Compatible with a variety of operating systems, can be data acquisition, analysis, comparison and other work.

• Simple operation: the software interface is friendly, man-machine dialogue, simple operation.

• Versatile inspection accessories: equipped with a variety of large aperture collection efficiency of fiber optic probes, complete sets of fiber probe Raman microscopes, can be equipped with a variety of sampling probes. A variety of fiber optic Raman probes, including those required for remote inspection, are suitable for dangerous goods detection.

• At the same time, it supports multi-system configuration: smaller size, can be connected to mobile phones, computers, etc. for detection operations, direct connection to direct mining, plug and play.

• It can be plugged directly into the microscopy system for micro-Raman applications.

3. Testing and study of Raman and fluorescence spectra of YIG/GGG films

3.1 Experimental setup

RMS1000 Miniature Raman Spectrometer  

SH-RAM-D20 Measuring Stand  

Experimental Test Sample - YIG &GGG

3.2 Experimental results

3.2.1 Raman pattern recognition of YIG/GGG thin films and GGG crystals:

YIG/GGG film is a ferromagnetic film that uses epitaxial growth to grow yttrium iron garnet (Y₃Fe₅O₁₂, referred to as YIG) on the substrate of gadolinium gallium garnet (Gd₃Ga₅O₁₂ for short). In optical communication, YIG/GGG film is one of the core components of 1.3-1.5 micron optical isolators. Yig and GGG materials belong to the same cubic crystal system, which has 25 Raman active vibration modes (3A_g+8E_g+14T_2g). A total of 11 vibration modes of 3A_g+8E_g can be observed in the VV polarization Raman scattering configuration, and 14 T_2g vibration modes can be observed with the VH polarization Raman scattering configuration. In a non-polarized Raman scattering configuration, the 14 T_2g vibration modes are essentially submerged in the 3A_g+8E_g vibration mode due to the scattering intensity of the 3A_g+8E_g vibration mode being much greater than the scattering intensity of the T_2g vibration mode. Therefore, in a non-polarized Raman scattering configuration, we can only observe 11 vibration patterns of 3A_g+8E_g, as shown in Fig. 1.

Fig 1. Non-polarized Raman scattering spectrogram of YIG/GGG films and GGG substrates

3.2.2 Identification of the crystal field energy level (fluorescence) of THE YIG/GGG film and the GGG crystal:

Fig. 2 Non-polarized Raman scattering spectra of YIG/GGG film and GGG substrate

As shown in Fig. 1, it is known that the Raman scattering information of the phonons of the YIG/GGG film is mainly concentrated in the range of 100-1000 wave numbers. Outside the greater than 1000 beam range, their signals are mainly derived from electron transitions in the YIG and GGG crystal fields, as shown in Fig. 2. Compared with the lattice vibration spectrum, the electron spectrum of rare earth garnet has received widespread attention. There are three reasons for concern: first, rare earth garnets can be used as materials for the preparation of advanced solid-state lasers, and second, crystal field theory methods can be applied to their electron spectroscopy, which is necessary for a complete understanding of the structure of rare earth iron garnets, especially for the understanding of the hypercommunication that exists in this rare earth garnet.

For this experimental work, we found that using Raman spectroscopy, the relative wave number displacement of the incident laser wavelength to the scattered light not only provides information about the phonon and electron energies in the garnet material, but also the relative scattering intensity of Raman provides information about the wave function of the electron energy level.

As far as the function of the RMS1000 Raman spectrometer developed by us is concerned, the complete phonon spectrum and corresponding electron emission spectrum of other functional materials such as garnet can be obtained with excitation at 785nm laser wavelength, and the Raman spectrum obtained with its high signal-to-noise ratio is at the same level as the research-grade spectrometer. The RMS1000 Raman Spectrometer provides a cost-effective scientific instrument for researchers engaged in materials science research.

Finally, we briefly introduce the relevant parameters and typical spectra of this high-performance Raman spectrometer, if there are users interested in this spectrometer, please leave a message in the background or contact us directly by phone.

4. Typical spectrum

5. Spectral consistency

Detection conditions: pure alcohol, 200ms integration time, ambient temperature 25 °C, batch sensitivity consistency±15%.

6. Check out the proficiency verification

Detection conditions: 0.5% ethanol, 5000ms integration time, ambient temperature 25 °C, batch sensitivity consistency ±15%.

8. Long-range detection verification

Detection conditions: 100% n-hexane, 3000ms integration time, ambient temperature 25 °C, 1m distance from the sample.

9. Penetration detection verification

Detection conditions: anhydrous sodium sulfate, 1000ms integration time, ambient temperature 25 °C, white plastic sample bottle.