Abstract: The invention is a photonic crystal laser including a photonic crystal slab laser cavity including InGaP/InGaAlP crystalline layers, the InGaP/InGaAlP crystalline layers having a relaxed strain at one or more etched surfaces and a higher strain at a plurality of quantum wells and at a distance from the one or more etched surfaces. The photonic crystal laser also includes electrical pads configured to receive an electrical signal the electrical pads attached to the photonic crystal slab laser cavity via an insulating layer, the photonic crystal laser configured to emit a laser light in response to the electrical signal. In another aspect, the invention features a photonic crystal detector including a photonic crystal slab cavity including InGaP/InGaAlP crystalline layers. In yet another aspect, the invention features a process to fabricate a photonic crystal laser cavity.