Quantum cascade laser in a master oscillator power amplifier configuration with Watt-level optical output power

Abstract

We present the design and realization of short-wavelength (λ = 4.53 μm) and buried-heterostructure quantum cascade lasers in a master oscillator power amplifier configuration. Watt-level, singlemode peak optical output power is demonstrated for typical non-tapered 4 μm wide and 5.25 mm long devices. Farfield measurements prove a symmetric, single transverse-mode emission in TM(00)-mode with typical divergences of 25° and 27° in and perpendicular to growth direction, respectively. We demonstrate singlemode tuning over a range of 7.9 cm(-1) for temperatures between 263K and 313K and also singlemode emission for different driving currents. The side mode suppression ratio is measured to be higher than 20 dB.

Broadly tunable monolithic room-temperature terahertz quantum cascade laser sources

“…Figure 2a displays the results when the DC bias is applied to the back section of the laser. As expected, the low-frequency pump o 2 shows significant red shift due to increase in the effective modal refractive index in the DBR section with bias current [20][21][22] . Figure 2b displays the tuning of mid-IR pumps when DC bias is applied to the front section of the laser.…”

“…By increasing DC current through these sections, we can electrically tune o 1 or o 2 . The mid-IR pump frequencies in our devices can only be red shifted with increase of DC current [20][21][22][23] ; however, THz emission frequency is given by the difference of the two mid-IR frequencies and thus can be both blue and red shifted depending on the choice of the mid-IR frequency to tune.…”

A patch-array antenna single-mode low electrical dissipation continuous wave terahertz quantum cascade laser

“…The easiness of scalability represents an advantage compared to the standard Master Oscillator-Power Amplifier (MOPA) devices, for which the single modality is strictly dependent on the effectiveness of the anti-reflection coating and thus on the target wavelength. 22 The electromagnetic field is out-coupled through a patch antenna that achieves surface emission in a single lobe pattern and it also has the advantage of avoiding cleaving procedures, 12,16,23 exploiting the metal-dielectric-metal optical properties. 24 Finally, as a double metal waveguide composes the laser, not only the heat dissipation is higher than for a single plasmon ridge, but the RC constant of the device is also lower.…”

Towards loss compensated and lasing terahertz metamaterials based on optically pumped graphene

“…can be seen in the case of germanium where a strong magnetic field must be applied in order to observe amplification [17]. Artificial gain media as quantum dots or quantum cascade materials appear to be more promising in this respect and have been demonstrated to strongly interact with plasmonic structures, however the fabrication and handling of quantum cascade lasers are not trivial [8,[18][19][20][21].…”