We present the status of quantum-cascade lasers without injector regions, based on a four- and five-level staircase,
respectively. First lasers were realized at a wavelength of ~ 10 &mgr;m. By applying an optimized design, we achieved high
performance injectorless quantum-cascade lasers emitting at ~ 6.7 &mgr;m. On the basis of this design, we investigated the
influence of doping density and the number of periods of active sections. A sample with a doping sheet density of
2.5x1010 cm-2 and 60 periods of active sections shows record low threshold current densities of 0.75 kA/cm2 at 300 K. Recently, we have further extended the wavelength range even down to ~ 4.2 &mgr;m.
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.