Features

• High Performance in a Compact Package
• 2 mm Diameter Clear Aperture
• MgO-Doped Lithium Niobate Crystal
• SMA RF Modulation Input Connector
• DC to 100 MHz
• Custom OEM Versions Available

Thorlabs free-space electro-optic (EO) phase lithium niobate modulator combines our experience with crystal growth and electro-optic materials. Our EO phase modulator uses MgO-doped lithium niobate for high power operation. The modulator has an SMA RF input, which is directly compatible with our HVA200 High Voltage Amplifier.

Our EO phase modulator provides a variable phase shift on a linearly polarized input beam. The input beam is linearly polarized along the vertical direction which is the Z-axis of the crystal. A voltage at the RF input is applied across the Z-axis electrodes inducing a change in the crystal's extraordinary index of refraction thereby causing a phase shift in the optical signal.

The control signal may be a DC or a time varying RF signal. When the control voltage is a time varying signal, the optical beam undergoes frequency modulation whereby some of the energy at the fundamental frequency is converted into sidebands separated from the fundamental frequency by the integer multiples of the modulating frequency. The amount of energy converted into sidebands is determined by the depth of modulation. The graph to the right shows a plot of relative sideband strength as a function of depth of modulation.

Specifications

• Wavelength Range: 1250 - 1650 nm
• Clear Aperture: 2 mm Diameter
• Input Connector: SMA Female
• Resonant Frequency Range: Broadband
• Half Wave Voltage: 136 V at 633 nm
• Input Capacitance/Impedance: 14 pF
• Max Optical Power Density: 2 W/mm² @ 532 nm, 4 W/mm² @ 1064 nm