We report the operation of a 2 THz quantum cascade laser based on a GaAs/Al0.1Ga0.9As heterostructure. Lasing action takes place between an isolated subband and the upper state of a 14 meV wide miniband. In pulsed mode, with a 3.16mm long device, we report a threshold current density of 115 A/cm2 at T = 4K, with a maximum measured peak power of 50 mW. The device shows lasing action in continuous wave up to 47K, with a maximum power in excess of 15 mW at T = 4K.
In this work we have investigated the operation of a recently demonstrated bound-to-continuum quantum cascade laser emitting at 2.9 THz under different active region doping densities. In addition, we have studied the injection efficiency as a function of the thickness of the Al0.15Ga0.85As barrier controlling the tunnel coupling between the superlattice miniband and the upper state of the laser transition. By tuning these two parameters threshold current densities as low as 52 A/cm2 and 83 A/cm2 were obtained at 5 K, corresponding to a reduction over the base design of 55% and 25% respectively. In both cases we attribute the improved threshold performance to a reduction of the parasitic leakage current. The decrease in threshold was always at the expense of a smaller laser dynamic operating range, which ultimately limited maximum operating temperatures in pulsed and continuous wave mode to 95 K and 80 K respectively.
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.