High power unidirectional-emission micro-cavity lasers and their array

Unidirectional emission micro-cavity lasers and their array are reported. Quantum cascade laser material with an emission wavelength centered at about 10 μm has been shaped into compact, notched ellipse-shaped cavities to obtain unidirectional emission. Up to 13 mW of light output peak power at room temperature is obtained with a unidirectional emission at far-field divergence angle of about 6.5° at full width of half maximum from the micro-cavity laser with structure size of 120 μm. Meanwhile, the micro-cavity lasers with different structure sizes are also fabricated. Their light output characteristics such as output power and threshold current density are compared and investigated in experiment. Finally the unidirectional emission micro-cavity laser array was also achieved to reach a higher power of 58 mW.