٥ Large range of accessible frequencies  molecule diversity ٥ With optical telecommunication components ٥ Rotation-vibration resonances of whole molecules ٥ Resonances specific of molecular species ٥ Resonances (width~100 kHz) clearly distinct, contrary to IR spectroscopy ٥ No heating, no ionization: molecule integrity ٥ Prefers liquid phase sampling for solute molecules at room temperature and pressure ٥ Measurement at low pressure (< 1 mbar) ٥ lots of molecules not in HITRAN/JPL/CDMS databases Scientific case Instrument properties First results on wave synthesis Submillimeter spectroscopy ٥ One laser diode wavelength stabilization Modeling (non-linear) phase and amplitude noise effects in cell transmission: Signal to noise depends on integration time, line strength, cell length… sub-ppm detectability seems achievable Conclusion and outlook