Mid-infrared resonant cavity light emitting diodes operating at 4.5 µm

Abstract

We report on a mid-infrared resonant cavity light emitting diode (RCLED) operating at the wavelength of 4.5 μm with narrow spectral linewidth at room temperature. Compared to a reference LED without a resonant cavity our RCLED exhibits (85x) higher peak intensity, (13x) higher integrated output power, (16x) narrower spectral linewidth and (7x) superior temperature stability. The device consists of a one-wavelength thick micro-cavity containing an Al 0.12 In 0.88 As/InAs 0.85 Sb 0.15 quantum well active region sandwiched between two high contrast AlAs 0.08 Sb 0.92 /GaSb distributed Bragg reflector mirrors, grown lattice-matched on GaSb by molecular beam epitaxy. The high spectral brightness, narrow linewidth and superior temperature stability, are attractive features, enabling these devices to be used for detection of N 2 O at 4.5 μm. We show that with only minor adjustments the gases CO 2 (4.2 μm) and CO (4.6 μm) are also readily accessible.

Advanced mid-infrared lightsources above and beyond lasers and their analytical utility

“…In addition, they thinned and roughened the emission side of the structure to improve light outcoupling, resulting in randomization of light direction and reduction of internal reflection and light outcoupling. With their 400 × 400 µm cascaded superlattice Reprinted and edited with the permission from [87].…”

“…Most recently, efforts have been focused on mitigating the low output power with broadband emission spectra at room temperature for developing next-generation MIR-LEDs, and new approaches of structure modification to increase the power output have been devised. Al-Saymari's team presented two so-called resonant cavity LED (RCLED) systems [ 86 , 87 ]. In these systems grown on GaSb substrate, the optical extraction efficiency limited by the large refractive index mismatch between the semiconductor and air has been addressed by placing the active structure between two DBRs.…”

“…Here, the first RCLED with a target wavelength of 4.2 µm consisted of lattice-matched AlAs 0.08 Sb 0.92 /GaSb DBR mirrors and a MQW InAs 0.90 Sb 0.10 active region [ 86 ]. The second RCLED, on the other hand, had a target wavelength of 4.5 µm with AlAs 0.08 Sb 0.92 /GaSb DBR mirrors and MQW Al 0.12 In 0.88 As/InAs 0.85 Sb 0.15 active region [ 87 ]. They could demonstrate for both RCLED systems that they have a significantly stronger electroluminescent as well as narrower emission spectrum compared to a reference MIR-LED without resonance cavity.…”

“…7 Schematic of a MQW resonant cavity LED structure showing the details of the AlInAs/InAsSb MQW in the active region of the p-i-n diode within the AlAsSb/GaSb DBRs, which form the microcavity. © 2020 Optica Publishing Group.Reprinted and edited with the permission from[87].…”

Resonant Cavity–Enhanced Photodiodes for Spectroscopy of CH Bonds

“…It has previously been reported that the resonance peak wavelength shifts with temperature, with the majority of the shift attributed to changes in refractive indices of the cavity layers. [ 14,15 ] Figure 2b shows the temperature dependence of the resonant wavelength for the two devices. The gradient of the two fit lines shows clearly that the peak shift due to temperature is very similar for both devices— for the InAsSb‐based device and for the InAs‐based device.…”