Researchers have simulated the implementation of a universal set of quantum gates, encompassing both single-qubit and two-qubit operations, using photonic qubits encoded in the orbital angular momentum (OAM) of light. The study focuses on spatial light modulators (SLMs) as a reconfigurable platform for photonic quantum information processing. This approach allows for software-defined control over the OAM of Laguerre-Gaussian (LG) light beams, representing a significant step towards photonic quantum computing.

The simulation was performed on a HOLOEYE LC 2012 transmissive SLM, incorporating a realistic three-channel noise model. This model, derived from the manufacturer's datasheet without free-parameter fitting, includes 8-bit quantification noise, twisted-nematic (TN) electronic and thermal noise, and phase-wrap clipping errors. The total calculated noise was σ_total = 92.4 mrad. All universal single-qubit gates ({X, Y, Z, S, T, H}) and two-qubit entangling gates ({CNOT, CZ, SWAP}) were simulated on a 512 × 512 computational grid.

Simulation results predict gate fidelities in the range of F = 0.9914 to 0.9936. Fork grating gates were primarily limited by TN noise, while phase gates achieved higher fidelity due to zero phase-wrap clipping errors. Furthermore, Bell state preparation, using an H-CNOT circuit, achieved F(Φ+) = 0.9914 fidelity after two SLM interactions. These results were benchmarked against six published experimental studies, which reported fidelities between 78% and 99.6%. An additional analysis identified the 450-532 nm wavelength range as optimal for the device's operation.