Raman Filters

Raman Filters by Avantier: Enhancing Precision in Raman Spectroscopy

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 the world of 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 intrusive laser line.

Raman Filters
Raman Filters

Raman Filters

Avantier is renowned for its commitment to producing top-tier Raman filters, perfectly tailored to the most demanding tasks. The key attributes of our Raman filters include:

  • High Transmission: Our filters boast exceptionally high transmission capabilities, allowing for the detection of even the faintest 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, providing flexibility to suit various 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.

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 pass band (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 for Raman Filters

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

Raman Filter

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

We invite you to reach out to us to explore custom specifications and discover how Avantier can collaborate with you to design and select optimal 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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