Topological lasing is typically enabled by two key mechanisms: effective time-reversal symmetry breaking, which generates the nontrivial topology, and gain-induced non-Hermiticity supplied by the pump. Here we introduce a class of chain-driven lattices where nontrivial Chern numbers emerge directly from the modulation of gain. In this respect, we realize topological lasing-capable models where the pump drives both the lasing action and the topological character of the system. By tuning the modulation period, we identify three distinct regimes: a pseudo-Hermitian regime, a $\mathcal{PT}$-broken phase, and ultimately a domain of topological edge state lasing. Remarkably, the periodic switching of gain can yield topological lasing dynamics on an otherwise trivial static lattice, even under saturable nonlinear conditions, promoting the topologically protected amplification of light. Our system allows for continuous external control between chiral and antichiral edge configurations, enabling codirectional edge transport and protected bulk channels in both broken and unbroken regimes.

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• Topological phases of matter
• Lattices
• Schroedinger equation