This article is part of a series documenting quantum computing technologies and their ecosystem – the differing approaches, the key players behind them, and the key technologies that are driving us towards a quantum future. Part one looked at superconducting qubits (materialized in key industry giants such as IBM and Google) and trapped ion qubits (through IonQ and Quantinuum).

In this second part, we’ll be looking at quantum photonics – a light-based technique of defining the quantum unit of computation, the qubit. We’ll take a brief look at the what and the why of quantum photonics, and then materialize it by focusing on two particular companies, their roadmaps, and their technologies: Toronto-based Xanadu Quantum Technologies (which is making a play for public Nasdaq listing this first quarter of 2026 at an estimated 3.6B$ enterprise valuation through a SPAC deal); and the Palo Alto, California-headquartered PsiQuantum (PSIQ.PVT, with an estimated 7B$ valuation buoyed by a 1$ billion worth Series E funding round in late 2025).