title: Broadband superluminescence, 5.9 μm to 7.2 μm, of a quantum cascade gain device.
abstract: The broadband electroluminescence of a quantum cascade device based on a multi-color active region covering the wavelengths 5.9 μm - 7.2 μm was measured. Anti-reflection coatings were applied on both cleaved facets to remove the Fabry-Pérot cavity and prevent the device from lasing. This allows the latter to be studied either as a superluminescent diode or a single-pass amplifier in order to determine its suitability as a source for low speckle imaging applications. At 243 K, the amplified spontaneous emission has a peak power of 38 μW that agrees well with a simple model of spontaneous emission intensity. The light of a similar structure could be modulated up to 1 GHz, limited by the RC constant of the device. The peak gain was measured from high-resolution luminescence spectra and determined to be 6.3 cm⁻¹, corresponding to a single-pass gain of 1.89.
authors.forename: Sabine
authors.initials: S
authors.lastname: Riedi
authors.forename: Francesco
authors.initials: F
authors.lastname: Cappelli
authors.forename: Stéphane
authors.initials: S
authors.lastname: Blaser
authors.forename: Pierre-Yves
authors.initials: PY
authors.lastname: Baroni
authors.forename: Antoine
authors.initials: A
authors.lastname: Müller
authors.forename: Jérôme
authors.initials: J
authors.lastname: Faist