Broadband Tunable Filter

Characteristic curve

Typical Transmission Spectrum and Tuning Dispersion of 5.0nm Filter over O-Band

Typical Transmission Spectrum and Tuning Dispersion of 6.0nm Filter over S, C, L-Band

 

Size

OE-BBTF-WM-P/S

 

OE-BBTF-WE-P/S

 

 

 

 

 

1,Light enters from the "Fiber Optic Input Collimator" and ultimately exits from the "Fiber Optic Output Collimator".

2,Collimator: Its function is to transform the divergent light emitted from the optical fiber into collimated light (parallel beams), and conversely, to efficiently couple collimated light from free space back into an optical fiber.

3,Grating: The grating operates based on the principles of diffraction and interference. According to the diffraction equation, light of different wavelengths is diffracted at different angles.

4,Fourier Transform Lens: This lens is used to focus the light dispersed by the grating and perform a Fourier transform. It focuses different wavelengths of light onto distinct spatial locations at its rear focal plane, thereby converting angular separation into spatial displacement.

5,Movable Aperture: This aperture physically blocks most of the light, allowing only a narrow range of wavelengths to pass through. By precisely moving this aperture laterally, different wavelength bands can be selected to pass, thereby tuning the central wavelength of the filter.

6,Anti-Fourier Transform Lens: This lens performs the inverse Fourier transform, reconverting the spatially filtered light field back into an angular distribution.

7,Grating: The second grating is used to compensate for the angular deviation introduced by the first grating, eliminate residual dispersion, and ensure the output beam is correctly aligned for coupling into the output fiber.