Interband cascade devices with switchable laser and superluminescence mode

Superluminescent diodes are usually hard to fabricate and cannot switch to lasing operation. We demonstrate a practical approach for creating devices that can function as a laser as well as a superluminescent diode. The operation mode is controlled by a distinct contact that enables electrical switching between those modes. For the demonstration of this principle, we fabricated devices based on interband cascade gain media. The devices showed superluminescent power of up to 200 μW. The electrically switchable operation combines the good alignment capabilities of a laser with the broadband, low coherence properties of a superluminescent diode.