The 2330nm mid-infrared filter is an optical filtering device operating in the mid-infrared band (typically referring to 3000nm to 10μm and above, with 2330nm falling within the transition region between near-infrared and mid-infrared). Its core function is to selectively transmit infrared light at specific wavelengths around 2330nm while blocking radiation from other bands. Its design must align with the spectral characteristics of mid-infrared light sources or detectors, such as the characteristic absorption peaks of certain gas molecules (e.g., methane, carbon dioxide) near 2330nm or the response bands of specific infrared sensors.

II. Core Technical Parameters and Performance Indicators

• Center Wavelength (CWL): Precisely positioned at 2330nm, it must strictly match the target light source or detection requirements, with deviations typically controlled within ±5nm.
• Peak Transmittance (Tp): High-quality products can achieve a transmittance of over 90% in the 2330nm band, with low-loss film designs further increasing it to over 95%, reducing signal attenuation.
• Blocking Range and Blocking Level: It must effectively block visible light (400–700nm) and other interfering infrared bands (e.g., 1550nm, above 3000nm), with a blocking level typically requiring OD4 (transmittance ≤0.01%) or higher to avoid stray light interference.
• Film Structure: Utilizes multilayer dielectric thin films (e.g., alternating layers of silicon dioxide and tantalum pentoxide deposited) to achieve high reflection or high transmission through optical interference effects; film uniformity directly impacts filtering precision.