Spectroscopy of optically pumped ammonia and deuterium oxide near 1 THz
Molecular gases like ammonia (NH<inf>3</inf>) and deuterium oxide (D<inf>2</inf>O) can be used as active media for optically pumped terahertz lasers (OPTL). In this paper we present spectroscopic measurement of chosen NH<inf>3</inf> and D<inf>2</inf>O lasing lines near 1 THz. Rotational-vibrational transitions are pumped by mid infrared quantum cascade laser (MIR QCL) which offers more precise tunability in MIR spectral range than standard optical pumping methods (CO<inf>2</inf>, N<inf>2</inf>O lasers). This allows to access new lasing lines. Frequency domain measurements of NH<inf>3</inf> and D<inf>2</inf>O under different pressure, pumping frequency and pumping power are performed. The results show high gain obtained for NH<inf>3</inf> (3,3) line at 1.073 THz and very low gain for D<inf>2</inf>O (4,3,2) line at 533 GHz due to the low population.
IR Vibration-Rotation Spectra of the Ammonia Molecule
The IR spectrum of the ammonia inversion vibration-rotation normal mode is obtained using Fourier Transform IR Spectroscopy and analyzed using Maple, to easily obatin the relation between the N-H bond length and the H-N-H bond angle. As expected, the absolute geometry of the ammonia molecule cannot be determined completely with information gleaned from this vibrational transition.
Strategies for glass based photonic system integration
There is a clear tendency to integrate more and more opto-electronic and micro-optical components like optical fibers, laser diodes, modulators, isolators, beam-splitting components and micro lenses in also increasingly dense and complex assemblies. The paper will discuss thin glass as a very promising base material for that kind of photonic packaging on interposer and board level including optical interconnection using fibers.