|
|
Svechnikov, S. I., Finkel, M. I., Maslennikov, S. N., Vachtomin, Y. B., Smirnov, K. V., Seleznev, V. A., et al. (2006). Superconducting hot electron bolometer mixer for middle IR range. In Proc. 16th Int. Crimean Microwave and Telecommunication Technology (Vol. 2, pp. 686–687).
Abstract: The developed directly lens coupled hot electron bolometer (HEB) mixer was based on 5 nm superconducting NbN deposited on GaAs substrate. The layout of the structure, including 30x20 mcm^2 active area coupled with a 50 Ohm coplanar line, was patterned by photolithography. The responsivity of the mixer was measured in a direct detection mode in the 25-64 THz frequency range. The noise performance of the mixer and the directivity of the receiver were investigated in a heterodyne mode. A 10.6 mum wavelength CW CO2 laser was utilized as a local oscillator.
|
|
|
|
Stevens, M., Hadfield, R., Schwall, R., Nam, S. W., Mirin, R., & Gupta, J. (2006). Fast lifetime measurements of infrared emitters using a low-jitter superconduct- ing single-photon detector. Appl. Phys. Lett., 89, 031109.
|
|
|
|
Stevens, M., Hadfeld, R., Schwall, R., Nam, S. W., & and Mirin, R. (2006). Quantum dot single photon sources studied with superconducting single photon detectors. IEEE J. Sel. Topics Quantum Electron., 12(6), 1255–1267.
|
|
|
|
Baryshev A., Hovenier J.N., Adam A.J.L., Kašalynas I., Gao J.R., Klaassen T.O., et al. (2006). Phase locking and spectral linewidth of a two-mode terahertz quantum cascade laser. Physics Letters, 89.
Abstract: We have studied the phase locking and spectral linewidth of an ~ 2.7 THz quantum cascade laser by mixing its two lateral lasing modes. The beat signal at about 8 GHz is compared with a microwave eference by applying conventional phase lock loop circuitry with feedback to the laser bias current. Phase locking has been demonstrated, resulting in a narrow beat linewidth of less than 10 Hz. Under requency stabilization we find that the terahertz line profile is essentially Lorentzian with a minimum linewidth of ~ 6.3 kHz. Power dependent measurements suggest that this linewidth does not approach the Schawlow-Townes limit.
|
|
|
|
Hovenier J.N., Adam A.J.L., Kašalynas I., Gao J.R., Klaassen T.O., Baryshev A., et al. (2006). Phase-locking on the beat signal of a two-mode 2.7 terahertz metal-metal quantum cascade laser. In Proc. Symp. IEEE/LEOS Benelux Chapter (pp. 125–128).
Abstract: We have studied the linewidth and phase-locking of a 2.7 THz quantum cascade laser by using a superconducting bolometer mixer. The 8 GHz beat signal is compared with a microwave reference with a feedback to the laser bias current. Phase locking has been demonstrated, resulting in an extremely narrow beat linewidth of less than 10 Hz. Under frequency-stabilization conditions we find that the line profile is virtually Lorentzian with a long-term minimum linewidth of the THz modes of about 6.3 kHz. Temperature dependent measurements suggestthat this linewidthdoes not approach the Schawlow-Townes limit.
|
|
