Raman Filters
In the realm of Raman spectroscopy, the critical component known as the Raman filter plays an indispensable role. These specialized optical filters, expertly crafted by Avantier, serve as meticulous gatekeepers in Raman analysis. Placed strategically within the optical beam path, these filters exhibit the remarkable ability to selectively transmit Raman scattered light to the spectrometer while effectively blocking the laser line.
Avantier is renowned for its commitment to producing top-tier custom Raman filters, perfectly tailored to the most demanding tasks. The key attributes include:
- High Transmission: Our filters boast exceptionally high transmission capabilities, allowing for the detection of even the faintest raman signals, ensuring no precious data goes unnoticed.
- Ultra-Steep Edge: With an ultra-steep edge, these filters can discern minuscule Raman shifts with utmost precision, ensuring the accuracy of your spectroscopic measurements.
- Deep Optical Blocking: Laser rejection is taken to the maximum level with our filters, thanks to their deep optical blocking, ensuring that unwanted laser interference is effectively eliminated.
- Durability: Our filters are fortified with hard coatings and meticulously manufactured without the use of adhesives, ensuring a longer filter life and consistent performance over time.
Your Choice of Raman Filters: Notch or Edge Filters
At Avantier, we offer both notch and edge filters used in Raman spectroscopy applications. Your choice between these filter types depends on the specific demands of your work. It’s important to note that individual filters are required for each laser wavelength employed.
Raman edge filters function as long-pass optical filters, efficiently blocking all wavelengths up to a specified cut-off point, while transmitting those above the cutoff. For instance, a 532 nm edge filter would absorb light up to 534 nm, effectively blocking the 532 nm laser line and permitting the detection of the Raman spectrum beyond 534 nm. These filters are known for their environmental stability and can have an indefinite lifespan with proper care.
Raman notch filters, on the other hand, create a sharp, well-defined band where light is blocked. This absorption band must align precisely with the laser wavelength in use, typically spanning only a few nanometers. For example, if you are working with a 532 nm laser, you would choose a notch filter with a central absorption at 532 nm. Notch filters allow the transmission of Raman spectrum above this wavelength, as well as any lower-wavelength light. Notably, they can be employed for both Stokes and anti-Stokes Raman scattering, offering greater versatility. However, it’s essential to be aware that they have a limited lifespan and may degrade over time.
Raman Laser Line Filters
Our Raman laser line filters are meticulously engineered to permit only a specific laser wavelength while effectively blocking all other ambient light. These bandpass filters play a pivotal role in cleaning up the laser beam signal and reducing noise. Avantier’s laser line filters boast exceptionally high transmittance within the passband (greater than 90 percent) and possess a narrow bandwidth of 1-3 nm. Furthermore, they exhibit a high optical density within the 300 to 1200 nm range, ensuring precise filtering performance.
Standard Specifications
Commitment to Precision Craftsmanship | Unwavering |
Materials | Fused Silica, NBK7, or equivalent |
Clear Aperture | > 80% |
Surface Quality | 60-40 scratch dig |
Edge Steepness | 0.5% of laser wavelength |
Transition Width | < 2% of laser wavelength (T=50% to OD6) |
Laser Damage Threshold | 1 J/cm² at 532 nm, 10 ns pulse width |
Laser Line Blocking | Optical Density > 6.0 |
Angle of Incidence | 0.0 +/- 2.0 degrees |
In Stock Raman Filters
Part Number | Laser Line | Wavenumbers(/cm) | Passband |
RL-4416-25 | 441.6 | <224 | 447.3-996.1nm |
RL-4579-25 | 457.9 | <216 | 463.9-668.4nm |
RL-4730-25 | 473.0 | <209 | 479.1-1066.9nm |
RL-4880-25 | 488.0 | <203 | 494.3-1100.8nm |
RL-5145-25 | 514.5 | <192 | 521.2-1160.5nm |
RL-5320-25 | 532.0 | <186 | 538.9-1200.0nm |
RL-5682-25 | 568.2 | <174 | 575.6-1281.7nm |
RL-6328-25 | 632.8 | <156 | 641.0-1427.4nm |
RL-6471-25 | 647.1 | <153 | 655.5-1459.6nm |
RL-6640-25 | 664.0 | <149 | 672.6-1497.7nm |
RL-7800-25 | 780.0 | <127 | 790.1-1008.0nm |
RL-7850-25 | 785.0 | <126 | 795.2-1770.7nm |
RL-8080-25 | 808.0 | <123 | 818.5-1822.6nm |
RL-8300-25 | 830.0 | <119 | 840.8-1872.2nm |
RL-9800-25 | 980.0 | <101 | 992.7-2000.0nm |
RL-10640-25 | 1064.0 | <93 | 1077.8-2000.0nm |
Custom Raman Filters
Please reach out to us to explore custom Raman Filters and discover how Avantier can collaborate with you to design and select optical components for your unique optical system. Your pursuit of precision in Raman spectroscopy deserves nothing less than the exceptional quality and expertise offered by Avantier.
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