MPLC-Based OAM Laser Transformer

We propose to demonstrate an OAM transformer based on the multi-plane light conversion (MPLC) technology and wavelength-division multiplexing. During the Base Period of this Phase I SBIR effort, we haveĀ 1.ĀĀ Āsuccessfully designed MPLC phase masks for producing various OAM modes. One of the MPLCs was especially for Boston University to be used for all-fiber visible light generation using orbital angular momentum mediated parametric nonlinearities;Ā 2.ĀĀ Āverified these designs using spatial-light modulators (SLMs); 3.ĀĀ Āsent these designs out for foundry fabrication by SILIOS Technologies;Ā 4.ĀĀ Āhave fabricated these phase masks in house and verified successful generation of the (OAM_0,40) mode using in-house phase masks. This was not originally planned in either the Base Period or Option Period. Coincidentally, UCF recently acquired a grayscale lithography machine, and we could not resist trying to make MPLCs ourselves. The ability to fabricate MPLCs in house not only will reduce the cost but also speed up design cycles in Phase II research. During the Base Period of Phase II research, we will 1) Design MPLC phase screens for an OAM mode transformer/multiplexer that can convert 3 Gaussian beams at three wavelengths, 1 micron, 1.5 microns and 2 microns, into 3 desired (superposition of) OAM modes ( Āwith Ā between ▒5 and ▒40) and multiplexed them into a single ring-core OAM fiber, 2) fabricate and assemble the above MPLCs using lithographically defined phase masks, and 3) in the Option Period, delivering a compact device with two LMA/SMF pigtails carrying 0.98 micron and 1.5 microns of light and produce two desired OAM modes in a ring-core OAM fiber, with one specific OAM mode for each wavelength. These OAM transformers are required for the degenerate SAM and non-degenerate OAM four-wave-mixing interaction in ring-core OAM fibers for wavelength translation, critical for naval applications.