Quantum cascaded superluminescent light emitting diodes with dual tilted waveguide structure

We present a novel dual tilted waveguide structure for superluminescent light emitting diodes (SLEDs), which consists of two tilted waveguides and a semi-annular waveguide. The novel waveguide structure utilizes a tilted mirror and a non-closed whispering gallery mode to suppress F‑P resonance. Furthermore, based on the material characteristics of the mid-infrared InGaAs/InAlAs quantum cascades (QC), we investigate the effects of the parameters of the dual tilted waveguide structure on the optical properties, such as the waveguide width, tilted angle, span-to-depth ratio, and heat dissipation spacing. We theoretically obtain a device with low reflectivity, low optical loss and good heat dissipation effect. Finally, we demonstrate the output characteristics of the device by simulation, and the results show that the novel waveguide structure can realize the output of one-side superluminescence light. The central wavelength of the device is ∼10 µm, and the spectrum of the full-width half-maximum is ∼2 THz. The device has directional output properties, with a parallel far-field divergence angle of ∼37.5°. This novel dual tilted waveguide structure shows a great potential in achieving the high power and wide spectral output of SLED.