LP1400 롱패스 필터(T>85%@1420-1750nm, OD4@200-1380nm)

Silicon Wafer Inspection

• The Physics: Pure silicon becomes transparent to light at wavelengths longer than ~1150nm.
• The Application: While a standard 1200nm filter works, this 1400nm filter pushes further into the SWIR range, often providing better contrast for specific dopants or backside alignment marks while completely blocking any ambient visible/NIR light that might cause noise.

Recommended Light Sources

• Broadband Tungsten-Halogen Lamp: This source emits a continuous, high-intensity spectrum covering the entire 1420–1750nm passband, ensuring maximum signal throughput for the InGaAs sensor and allowing the system to fully utilize the high-transparency window of silicon for detecting internal defects or dopant variations.

Laser Beam Cleanup & Eye-Safe Systems

• The Physics: The 1550nm wavelength is the standard for "eye-safe" laser rangefinding and telecommunications.
• The Application:LIDAR/Rangefinding: It blocks interference from sunlight (visible/NIR) and other laser sources (like 905nm or 1064nm lasers) while letting the 1550nm signal pass.Telecom: Used in free-space optics to filter out pump diode noise (often 980nm) while passing the C-band and L-band signals (1530–1625nm).

Recommended Light Sources

• 1550nm Fiber Laser or C/L-Band Laser Diode: These sources emit specifically within the filter’s high-transmission window (1530–1625nm), allowing for high-power "eye-safe" operation (critical for long-range LIDAR) while the filter effectively strips away residual 980nm pump light or blocks environmental noise (like sunlight and shorter-wavelength lasers) at the receiver.