FREE-SPACE RESONANTLY ENHANCED AMPLITUDE MODULATORS
QUBIG provides resonantly enhanced, very efficient polarisation shifters that can be converted with appropriate polarisation optics into high-frequency amplitude/intensity modulators. Large spectral bandwidth, very low insertion loss, high optical damage thresholds and extinction ratios up to 30dB enable a wide range of applications.
The spectrum ranges from mode locking, optical chopping in industry to Lock-In amplification, multiplexing of single photon trains as well as rapid polarisation modulation for state manipulations in novel Quantum technology systems. Together with matching drivers that include cutting edge features a simple and quick implementation in experimental setups is provided.
Altered Laser Property: Polarization/Amplitude
Effect on the Laser Light: Polarisation / Amplitude Modulation
Electro-optic amplitude modulators (AM) are essentially Pockels cells consisting of a single or multiple electro-optic crystals with zero or compensated natural birefringence. Applying an electric field to the crystal induces a change in both the ordinary and extraordinary indices of refraction giving rise to an electric field dependent birefringence which leads to a change in the polarisation state of the transmitted optical beam. In this way the electro-optic crystal acts as a variable waveplate with retardance linearly dependent on the applied electric field. By placing a linear polariser after the modulator, the beam intensity through the polariser varies quasi sinusoidally with linear change in applied voltage. The voltage required to produce a retardance of π radians is called the halfwave voltage or simply Vπ.