Free-Space High-Speed Modulators – Phase, Intensity, Wavelength

We offer a broad selection of free-space optical modulators for phase and intensity control, tailored to a wide range of application requirements. These modulators are based on various electro-optic crystals, as detailed in the table below. Key design considerations include aperture size, operating wavelength, optical power handling, and drive voltage. For most applications, a 3 mm aperture is sufficient. In these cases, we offer analog drivers with charge drift cancellation, as well as built-in resonant drivers that are compatible with standard function generators. For applications requiring larger apertures — up to 10 mm — we provide matched high-voltage pulse drivers and long-crystal configurations optimized for analog modulation

Property LiNbO3 LiTaO3 KDP ADP RTP
Optical Transmission Range (µm) 0.4 – 5.2 0.25 – 5.5 0.2 – 1.5 0.18 – 1.3 0.35 – 4.5
Hygroscopicity No No Moderate Strong No
Electro-Optic Coefficient (r33, pm/V) ~30.8 ~30.0 ~10.5 (r63) ~9.0 (r63) ~13.8 – 15.0 (r33)
Dielectric Constant (Ɛr) ~28 (z-axis) ~44 (z-axis) ~50 (z) ~60 (z) ~24
Piezoelectric Constant (d33, pC/N) ~6.0 ~2.5 High (~12-25) High (~15-30) Low (~1)
Electrode Application Method Transverse / Waveguide Transverse / Waveguide Transverse Transverse Longitudinal / Transverse
Optical Damage Threshold (GW/cm²) ~0.5 – 1 ~0.5 – 1 ~4 – 6 ~3 – 5 > 10
Thermal Stability (°C) Up to 1000 (Curie ~1140) Up to 600 (Curie ~605) Low (~120) Low (~110) Stable up to 70
Refractive Index (n @ 1.55 µm) ~2.20 ~2.18 ~1.50 ~1.48 ~1.82