From left to right: Model 400X, Model 442X, and Model 485X. Models 400X are covered by U.S. Patent #5,189,547. Models 4851 and 4853 are covered by U.S. Patent #5,414,552.
Our popular line of phase modulators are ideally suited for applications in atomic physics (including atom-trapping and cooling experiments), laser-frequency stabilization, high-resolution spectroscopy, and laser-guide-star systems for astronomy. We offer broadband modulators that can be used at a wide range of frequencies and resonant modulators that operate at a single frequency with much lower drive-voltage requirements. When used properly, the New Focus electro-optic phase modulators can provide efﬁcient phase modulation with extremely low unwanted amplitude modulation and insertion loss. The key to obtaining this pure phase modulation is good optical alignment of the beam to the crystals propagation axis and accurate orientation of the lasers electric ﬁeld with the crystals electro-optic axis. New Focus makes proper alignment easy: simply pass the beam through the mechanical apertures.For applications requiring higher optical damage thresholds, see our KTP phase modulators. For applications requiring even higher efficiencies and modulation depths, see our high-efficiency phase modulators.
These models can operate over a broad range of frequenciesfrom DC to 100 MHz. The Model 3211 broadband-modulator drivers can be used to drive these modulators in the DC-to-0.6-MHz range.
For these devices, we use a resonant tank circuit to maximize power transfer from driver to crystal, thereby maximizing the voltage across the crystal. These built-in resonant circuits lower required drive voltages by a factor of nearly 10. To optimize performance at every frequency, these modulators are built with ﬁxed components, so they are only slightly tunable around the resonant frequency. If your needs change, we can replace the resonant circuit for a modest fee. The Model 3363 resonant-modulator driver can be used to drive these modulators.
For Models 442X and 443X, the crystal is placed in a microwave cavity that is designed to resonate at the particular frequency you specify when ordering. A tuning slug allows adjustment of the resonant frequency over a range greater than 100 MHz. The frequency range of these modulators extends to 4.6 GHz so they can be used in trapping and cooling experiments that involve cesium. The Model 3363 driver can be used to drive these modulators up to 2 GHz.
Operating at 6.8 or 9.2 GHz, these are the highest-frequency bulk phase modulators on the market today. The Models 485X are the perfect tools for use in atom trapping and cooling experiments involving cesium and rubidium because their resonant frequencies correspond to the ground-state energy splitting of these atoms. In addition, these high-frequency phase modulators can be used in optical comb generators, which are useful for high-resolution spectroscopy. Each Model 485X consists of an electro-optic crystal in a resonant microwave cavity. The cavity is designed so that the microwave phase velocity and the optical group velocity through the crystal are matched, thus ensuring efﬁcient phase modulation and low drive-voltage requirements. The cavity is equipped with a tuning slug that allows manual adjustment of the resonant frequency over a 100-MHz range. Other frequencies in the 6-to-10-GHz range are also available. If you are interested in a custom frequency, please contact us for details.When ordering any resonant modulator, please specify the resonant frequency.