We demonstrate mid-infrared continuous-wave vertical-cavity surface-emitting lasers based on Bragg mirrors using
IV-VI semiconductors and BaF2. This material combination exhibits a high ratio between the refractive indices of up to
3.5, leading to a broad mirror stop band with a relative width of 75 %. Thus, mirror reflectivities higher than 99.7 % are
gained for only three layer pairs. Optical excitation of microcavity laser structures with a PbSe active region results in
stimulated emission at various cavity modes between 7.3 μm and 5.9 μm at temperatures between 54 K and 135 K. Laser
emission is evidenced by a strong line width narrowing with respect to the line width of the cavity mode and a clear laser
threshold at a pump power of 130 mW at 95 K. Furthermore, we study a similar microcavity but without an active
region. The resonance of such an empty microcavity has a narrow line width of 5.2 nm corresponding to a very high
finesse of 750, in good agreement to transfer matrix simulations and to the expected mirror reflectivities.
Operation of IV-VI vertical-cavity surface-emitting lasers emitting in the mid-infrared is reported. The microcavity laser structures were grown by molecular-beam-epitaxy on BaF2(111) substrates. The stimulated emission is generated in PbTe quantum wells embedded in high finesse Pb0.95Eu0.05Te/EuTe microcavity structures by optically pumping with fs and ns laser pulses. Laser samples were designed for operation at 2 K, at 70 K and at room temperature with emission at 6 mm, 4.8 mm and around 3 mm, respectively. At a wavelength of 3.1 mm, laser operation is obtained up to a temperature of 65°C, limited by nonradiative recombination processes. The temperature dependence of the emission is explained in terms of the strong temperature dependence of the energy band gap of the lead salt compounds as compared to the microcavity resonance energy in agreement with envelope function calculations of the quantum well energy levels.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.