Investigation of mechanically induced long period grating by 3-D printed periodic grooved plates

In this paper, we propose a new technique to fabricate long period gratings (LPGs) by mechanically applying a force to an optical fiber enclosed in a low-cost periodic 3-D printed polymeric structure. We have developed novel interdigitated grating design and studied different periods, acquiring transmission spectra over a wavelength range of 1300–1700 nm. By using the proposed technique, we experimentally analysed in detail the behaviour of gratings inscribed in standard single mode fiber SMF-28 with and without acrylate coating, effects of applied weight and grating length, showing that the resonance wavelengths can be configured according to these parameters. The realized LPGs show an attenuation band with a depth up to 30 dB and total grating lengths ranging from 27 mm to 40 mm for various periods. The results also show that the realized LPGs are only slightly polarization dependent, have negligible insertion losses, low spectral ripples, and offer high tunability and repeatable. Furthermore, the presented technique is simple, inexpensive, easy to implement, tunable and with a high degree of customization of the design parameters accordingly to the applications.