1550nm femtosecond lasers have unique application value in the field of biological imaging, especially in optical coherence tomography (OCT) and multiphoton microscopy. The following is a detailed introduction to these applications:
1. Optical coherence tomography (OCT)
Principle:
OCT is a non-invasive biological tissue imaging technology that uses near-infrared light to obtain high-resolution cross-sectional images of biological tissues. Lasers with a wavelength of 1550nm are particularly useful in this field because it corresponds to one of the lowest attenuation windows of optical fibers, which means that light can travel farther with less loss.
Applications:
- Ophthalmic imaging: 1550nm femtosecond lasers are used for ophthalmic examinations, especially high-resolution imaging of the retina and cornea. This helps diagnose and monitor a variety of eye diseases, such as glaucoma, diabetic retinopathy, etc.
- Skin imaging: used for diagnosis and treatment monitoring of skin diseases, such as early detection of skin cancer.
- Cardiovascular imaging: used for imaging the inner wall of blood vessels to help identify atherosclerotic plaques and other vascular abnormalities.
Advantages:
- Deep penetration: 1550nm laser has good tissue penetration and is suitable for deep tissue imaging.
- High resolution: OCT can provide image quality similar to that of living tissue slices, usually with a resolution of several microns.
- Non-invasive: No tissue sampling or staining is required, reducing patient pain and risks.
2. Multiphoton microscopy
Principle:
Multiphoton microscopy uses near-infrared light (usually 700nm to 1300nm or longer wavelengths) for imaging. 1550nm femtosecond lasers are also used for multiphoton microscopy due to their deeper tissue penetration and lower phototoxicity.
Applications:
- Live cell imaging: Dynamic processes of cells in living animals can be observed.
- Neuroscience: Study neuronal activity, synaptic connections, and neural network function.
- Drug delivery and efficacy evaluation: Evaluate the distribution of drugs in tissues and their effects.
Advantages:
- Tissue penetration: The deep penetration of 1550nm lasers allows imaging of deeper tissue layers.
- Reduce phototoxicity: Compared with short-wavelength lasers, 1550nm lasers are less damaging to biological tissues and are more suitable for long-term observation.
- High-contrast imaging: Multiphoton excitation can provide high-contrast fluorescence signals, which helps to distinguish different tissue structures.
3. Nonlinear optical imaging
1550nm femtosecond lasers can also be used in nonlinear optical imaging techniques such as second harmonic generation (SHG) and third harmonic generation (THG), which use nonlinear optical effects to produce high-contrast images.
4. Micro-nano processing
The high pulse energy and extremely short pulse width of 1550nm femtosecond lasers make them very suitable for micro-nano processing of biological samples, such as the fabrication of microfluidic channels and micromanipulation of cells.
5. Other applications
- Confocal microscopy: 1550nm lasers can also be used in confocal microscopy to improve imaging depth and resolution.
- Fluorescence lifetime imaging (FLIM): It is used to quantitatively analyze the lifetime information of fluorescent molecules in biological samples.
In short, 1550nm femtosecond lasers are widely used in the field of biological imaging, especially in cases where deep tissue imaging and high-resolution imaging are required, they provide unique advantages. If you need more detailed information or specific application cases, please feel free to let us know.
