Wavelength Dependent Performance of Spatial Light Modulator-based OAM Beam Generator and Detector

Abstract

In this paper, we report the wavelength-dependent performance of orbital angular momentum (OAM) beam generation and detection using a spatial light modulator (SLM). To characterize the wavelength dependency of the OAM beam generation and detection, we used a 10 Gbps non-return to zero ON–Off Keying (NRZ-OOK) modulated optical signal, and we measured the optical signal-to-noise ratio (OSNR) values and Q values over the C band. In this study, we have used OAM beams with topological charge (l) values ±1, ±2, and, ±3. The results reveal that the measured OSNR values and Q values show a variation of 1 dB over the entire C-band. In this work, we have also reported the BER performance of OAM beams with a topological charge of ±1, ±2, and ±3 at wavelengths of 1530 nm, 1550 nm, and 1565 nm. These results also show that for all topological change values, the required received power to achieve the Pre-FEC BER value (1 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−3</sup> ) over the entire C-band depends on the wavelength of operation and exhibits a variation of 1.7 dB. The experimental results indeed show that the optical performance of the generation and detection of OAM beams strongly depend on the operating wavelength. Thus, this study can be beneficial for designing optical links using OAM multiplexing along with a wavelength division multiplexed (WDM) transmission system.