The Long Period Grating (LPG) from DK Photonics is a specialized optical fiber component designed to manipulate light propagation within fiber optic systems. Unlike traditional fiber Bragg gratings that reflect specific wavelengths, LPGs induce coupling between the core mode and forward-propagating cladding modes, resulting in wavelength-selective attenuation. This unique mechanism enables the LPG to act as a highly effective notch filter, providing precise spectral loss at designated wavelengths while maintaining low insertion loss for other wavelengths.

The structure of the Long Period Grating consists of periodic variations in the refractive index along the length of the optical fiber. These periodic modulations are engineered to satisfy phase-matching conditions for specific co-propagating modes, allowing for efficient energy transfer from the core to the cladding. The result is a customizable spectral response, making LPGs particularly valuable in applications such as gain flattening filters (GFF) for erbium-doped fiber amplifiers (EDFA), optical fiber sensing, and advanced telecommunication systems.

DK Photonics’ LPGs are compatible with standard single-mode fibers like SMF-28, ensuring seamless integration into existing fiber networks. The devices are available with various terminations, including bare fiber, FC/UPC, or FC/APC connectors, to accommodate diverse installation requirements. With a typical full width at half maximum (FWHM) ranging from 0.5 to 3 nm and a high attenuation at the center wavelength, these gratings deliver reliable, spectrally selective performance. Their robust design and customizable parameters make them suitable for both laboratory research and demanding field applications where precise wavelength control and low insertion loss are critical.