A THz optical modulator for a continuous-wave laser using a hollow-core photonic crystal fiber (HC-PCF) was proposed and theoretically analyzed. Lightwaves traveling through the HC-PCF is modulated by interactions with coherently driven Raman-active molecules in the core. The coherent molecular motion is excited by a pulse train having an interval between successive pulses shorter than the molecular dephasing time. In principle, a rotational transition of molecular hydrogen (S 0 (1)) at a pressure of 1 atm has a long enough dephasing time to maintain molecular coherence during a 1 GHz commercially available mode-locked pulse train. Optimization of the waveguide dispersion would enable phase-matching between the probe beam and generated sidebands during optical modulation. The proposed scheme would be achievable with a reasonable pump beam power and HC-PCF length, and with a feasible pressure of molecules in the core.A THz optical modulator for a continuous-wave laser using a hollow-core photonic crystal fiber (HC-PCF) was proposed and theoretically analyzed. Lightwaves traveling through the HC-PCF is modulated by interactions with coherently driven Raman-active molecules in the core. The coherent molecular motion is excited by a pulse train having an interval between successive pulses shorter than the molecular dephasing time. In principle, a rotational transition of molecular hydrogen (S 0 (1)) at a pressure of 1 atm has a long enough dephasing time to maintain molecular coherence during a 1 GHz commercially available mode-locked pulse train. Optimization of the waveguide dispersion would enable phase-matching between the probe beam and generated sidebands during optical modulation. The proposed scheme would be achievable with a reasonable pump beam power and HC-PCF length, and with a feasible pressure of molecules in the core.

Applied SciencesOct 12, 20180 citations

Prospects for continuous-wave molecular modulation in Raman-active microresonators

J. T. Karpel, David C. Gold, Deniz D. Yavuz

We propose the extension of existing molecular modulation techniques for continuous-wave optical modulation to Raman-active microresonators. Intense pump and Stokes modes inside a microresonator prepare a high coherence of the Raman transition between two ro-vibrational states. With the coherence prepared, any laser in the optical region can be coupled to the microresonator and be modulated. We perform numerical simulations which predict that these "microresonator-based molecular modulators" could have modulation efficiencies on the order of 1% at 10 THz-scale frequencies for any optical wavelength.We propose the extension of existing molecular modulation techniques for continuous-wave optical modulation to Raman-active microresonators. Intense pump and Stokes modes inside a microresonator prepare a high coherence of the Raman transition between two ro-vibrational states. With the coherence prepared, any laser in the optical region can be coupled to the microresonator and be modulated. We perform numerical simulations which predict that these "microresonator-based molecular modulators" could have modulation efficiencies on the order of 1% at 10 THz-scale frequencies for any optical wavelength.

Optics ExpressNov 7, 20194 citations

Coherently Driven Molecular Vibrations and Light Modulation

E. Garmire, F. Pandarese, Charles Hard Townes

Physical Review LettersAug 15, 1963220 citations

High-frequency modulation of continuous-wave laser beams by maximally coherent molecules

Deniz D. Yavuz

We suggest a technique where a molecular Raman transition is prepared near a maximally coherent state with continuous-wave (CW) laser beams. The key idea is to put the molecules inside a high-finesse cavity and to drive the molecular transition with two lasers whose frequency difference is slightly detuned from the Raman resonance. In this regime, the molecules become very efficient CW modulators with a modulation frequency that can be as high as $100\phantom{\rule{0.3em}{0ex}}\mathrm{THz}$ .We suggest a technique where a molecular Raman transition is prepared near a maximally coherent state with continuous-wave (CW) laser beams. The key idea is to put the molecules inside a high-finesse cavity and to drive the molecular transition with two lasers whose frequency difference is slightly detuned from the Raman resonance. In this regime, the molecules become very efficient CW modulators with a modulation frequency that can be as high as $100\phantom{\rule{0.3em}{0ex}}\mathrm{THz}$.

Physical Review AJul 26, 200712 citations

100\phantom{\rule{0.3em}{0ex}}\mathrm{THz}