Sulfide sulfur based glass infrared optical fiberBased on sulfur based glass, it has a wide infrared transmission range (usually 1.1-6.5 μ m, some can reach more than 10 μ m), high refractive index, low softening temperature, and excellent chemical stability, playing a key role in multiple fields, as follows:
1. Infrared spectroscopy analysis and chemical sensing
Principle: Utilizing the interaction between evanescent waves on the surface of optical fibers and the substance to be tested, component analysis is achieved by detecting infrared absorption spectra.
Application:
Environmental monitoring: detecting trace gases in the air (such as ethanol, trichloromethane) and pollutants in water sources (such as tetrachloroethylene).
Industrial process control: Real time monitoring of the curing reaction of thermoplastic polyimide composite materials, or detection of solvent content such as ethyl ketone in liquids.
Biomedical: Analyze the infrared characteristic spectrum of healthy human lung cells, track the effects of toxins on cells, and assist in early diagnosis of tumors.
Advantages: Anti electromagnetic interference, corrosion resistance, and can achieve remote, in-situ real-time monitoring in high temperature or toxic environments.
2. Infrared imaging and thermal imaging
Principle: Transmit infrared spectral scenes to mid infrared cameras through fiber optic bundles to achieve image reconstruction.
Application:
Military field: used in infrared countermeasure systems to guide laser output beams; Or detect rocket and tank exhaust through thermal imaging.
Industrial testing: monitoring equipment overheating areas to prevent malfunctions.
Advantages: Fiber bundles have flexibility and can adapt to complex scenarios; High imaging resolution, for example, a 64 × 64 pixel fiber optic bundle has achieved 2-meter length transmission.
3. High power laser transmission
Principle: The low phonon energy (about 350cm ⁻¹) and low non radiative transition rate of sulfur based glass enable it to withstand high-power lasers.
Application:
Industrial processing: Transmission of CO ₂ laser (10.6 μ m) for cutting, drilling, or welding.
Medical surgery: Transmitting Er: YAG laser (2.94 μ m) for precise cutting or skin disease treatment.
Advantages: The power density can reach 11.8MW/cm ² (2-meter long fiber), and the fiber is undamaged.
4. Temperature sensing and thermal monitoring
Principle: Based on the thermistor effect of sulfur based glass, temperature measurement is achieved by monitoring changes in resistance.
Application:
Health monitoring: non-invasive detection of sweat glucose concentration, replacing fingertip blood collection; Or monitor the temperature changes of athletes during training.
Battery management: In situ monitoring of the electrolyte composition and temperature inside the battery to evaluate its condition.
Advantages: High sensitivity, able to distinguish temperature changes of 0.1K within the range of room temperature to 823K.
5. Fiber amplifiers and lasers
Principle: Rare earth doped sulfur based glasses (such as Nd ³ ⁺, Er ³ ⁺) have a greatly excited cross section and can achieve optical amplification.
Application:
In the field of communication, we produce mid infrared fiber amplifiers to compensate for signal transmission losses.
Research field: Developing near-infrared to mid infrared (1-4 μ m) lasers for spectral analysis or material processing.
Advantages: The nonlinear coefficient is about 1000 times that of quartz glass, and the quantum efficiency is high.
6. Special environmental sensing
Principle: Utilizing the insensitivity of sulfur based glass to moisture, combined with fiber optic sensing technology.
Application:
Soil detection: By connecting a conical transparency meter to an optical fiber, volatile and non-volatile organic compounds in the soil can be detected remotely.
Organic synthesis: Real time monitoring of reactant concentration and temperature changes, optimizing process conditions.
Advantages: Wide detection range, covering various molecular vibrational spectra (such as 3-12 μ m).