685nm Optical Bandpass Filter (FWHM 20nm)

The 685nm optical bandpass filter is designed to transmit light centered at 685nm with a Full Width at Half Maximum (FWHM) of 20nm. It offers precise wavelength control and high transmission efficiency, making it a reliable choice for applications in biomedical imaging, fluorescence analysis, and optical communication requiring spectral isolation in the deep red region of the spectrum.

---

Standard Specifications:

• Type: VIS/NIR Bandpass Filter, Interference Filter
• Coating Type: Hard-coated for superior durability and long lifespan
• Center Wavelength (CWL): 685nm ± 2nm
• Full Width at Half Maximum (FWHM): 20nm ± 2nm
• Blocking Range: 200nm – 1200nm
• Blocking Depth: OD4, OD5, OD6, or higher
• Peak Transmission: > 90%
• Thickness: 1.0mm, 1.1mm (custom thicknesses available)
• Sizes: Round or square (e.g., φ12.5mm, φ25.4mm, φ50mm)
• Clear Aperture: > 90%
• Material: Fused Silica, B270

---

Custom Options:

• Bandwidth: Adjustable FWHM options (e.g., 10nm, 15nm, 25nm, 30nm, 35nm, 40nm,45nm, 50nm).
• Angle of Incidence (AOI): Tailored for specific application needs.
• Blocking Depth: Custom OD levels to meet specific requirements.
• Size: Round or square dimensions up to 150mm x 150mm.
• Material Thickness: Custom thicknesses available on request.
• Transmission and Blocking Range: Configurable within 200nm – 2000nm.

---

Applications:

• Fluorescence Microscopy: Isolates specific red emission signals for improved imaging contrast.
• Biomedical Imaging: Enhances visualization of tissues and dyes in diagnostic systems.
• Spectroscopy: Provides narrowband filtering for accurate spectral measurements.
• Optical Communication: Supports specific wavelength channels in data transmission systems.
• Agricultural Imaging: Captures chlorophyll fluorescence and other vegetation indices.
• 3D Imaging: Improves depth perception by filtering specific red spectrum wavelengths.
• Laser Applications: Ideal for laser alignment and beam shaping in the red spectrum.