SP1310 단거리 통과 필터(T>90%@750-1300nm, OD5@1350-2070nm)

Silicon Wafer & Solar Cell Inspection

Silicon becomes transparent to light at wavelengths longer than ~1100 nm. By using this filter with an InGaAs camera, you create a perfect "transparency window" between 1100 nm and 1300 nm.

• Why use this filter: Standard InGaAs sensors are sensitive up to 1700 nm. If you do not block the longer wavelengths (1350–1700 nm), the image can suffer from chromatic aberration (blurring) or thermal noise. This filter restricts the camera to the high-resolution "sweet spot" of silicon transparency.
• Use Case: Inspecting defects inside silicon ingots, wafers, or MEMS devices, or checking alignment markers on the backside of a wafer.

Recommended Light Sources

• High-Power SWIR LEDs (1150 nm or 1200 nm): These emit precisely within the target "transparency window" (1100–1300 nm) of silicon, providing high contrast and minimal heat while reducing the burden on the filter to block longer wavelengths.
• Tungsten-Halogen Lamps: These provide continuous, broad-spectrum illumination that fully saturates the 1100–1300 nm window, ensuring maximum signal intensity for detecting subtle backside alignment markers or internal cracks that require full-spectrum coverage.

"Water-Blind" Imaging (Moisture Removal)

Water has a massive absorption peak at 1450 nm. Light in that range is heavily absorbed by moisture, making water appear black.

• Why use this filter: By cutting off at 1310 nm, this filter effectively blocks the 1450 nm water band. This allows you to inspect moist organic materials (like food or biological tissue) without the image being darkened or obscured by water content. It allows for "deep tissue" imaging in the NIR-IIa window (1000–1300 nm) where scattering is low but water absorption hasn't yet taken over.

Recommended Light Sources

• Broadband Halogen or Tungsten Lamps: These provide continuous, high-intensity illumination across the entire 1000–1300 nm window, ensuring maximum photon penetration depth for thick biological samples or food products before the filter blocks the water absorption bands.
• SWIR LEDs (1050 nm or 1200 nm): These emit cool, targeted light within the low-scattering window, preventing heat damage to sensitive moist samples (like tissue or produce) while efficiently concentrating energy where the filter transmits best.