There is currently considerable interest in terahertz (THz) difference frequency generation (DFG) utilizing near-resonant intersubband nonlinearity in quantum cascade lasers and other quantum well heterostructures. Such devices were shown to operate at room temperature, but their power demonstrated so far has been rather low. In all previous works the intracavity configuration was studied, in w...

Portable terahertz (THz) frequency comb sources are highly desired for applications in rotational molecular spectroscopy and sensing. To date, direct THz quantum cascade laser (QCL) generation is not achievable at room temperature. However, based on intracavity difference (DFG) mid-infrared (mid-IR) QCLs a promising alternative. Here, we present numerical study of DFG-QCL formation mid-IR self-...

We report on an asymmetric high energy dual optical parametric amplifier (OPA) which is capable of having either the idlers, signals, or depleted pumps, relatively phase locked at commensurate incommensurate wavelengths. Idlers and signals can be order 200 mrad rms better, corresponding to a 212 as jitter λ =2 µ m. The arm OPA outputs combined 3.5 mJ signal idler, while low 1.5 mJ, with entire ...

Design, performance characteristics, and application of a room temperature mid-infrared laser spectrometer are reported. This compact instrument is based on differencefrequency mixing of a widely tunable external-cavity diode laser and a diode-pumped monolithic Nd:YAG ring laser in periodically poled lithium niobate (PPLN). The differencefrequency tuning range of 3.98 μm to 4.62 μm was sufficie...

Benzene is a very important molecule in variety of industrial, environmental, and chemical systems. In combustion, benzene plays an essential role the formation growth polycyclic aromatic hydrocarbons soot. this work, new laser-based diagnostic presented to make quantitative, interference-free, sensitive measurements mid-infrared (MIR) region. The based on widely tunable difference-frequency-ge...

We theoretically and numerically study the difference frequency generation and the signal amplification bandwidth together with the pump wavelength acceptance for counterpropagating optical parametric amplifiers. It is shown that the specific advantage of those amplifiers is that the DFG and amplification bandwidth is much narrower than in a co-propagating scheme, thus making it possible to shi...

In view of in vivo surgical smoke studies a difference-frequency-generation (DFG) laser spectrometer (spectral range 2900-3144 cm(-1)) and a Fourier-transform infrared (FTIR) spectrometer were employed for infrared absorption spectroscopy. The chemical composition of smoke produced in vitro with an electroknife by cauterization of different animal tissues in different atmospheres was investigat...

We present a novel mid-IR source based on optical parametric chirped pulse amplification (OPCPA) generating 96 fs pulses (9.0 cycles) at 3.2 mm with an energy of 1.2 microJ, at a repetition rate of 100 kHz. The amplified spectrum supports a minimum Fourier transform limited pulse duration of 45 fs, or 4.2 cycles. Our use of OPCPA allows the direct amplification of few-cycle pulses at this mid-I...

Electro-optic dendrimer was used to generate CW terahertz radiation via difference frequency method. In case of electro-optic excitation, the pump-THz conversion is not limited either by emission saturation or by heat dissipation. Especially, the difference frequency generation (DFG) uses two-photon excitation that eliminates the use of a femtosecond pulsed laser and allows for producing both c...