Research Topics of Modulators Group

The Mach-Zehnder Modulator structure is suited not only for standard on-off-keying modulation, but also for enhanced new modulation schemes like Duobinary or Differential Phase Shift Keying (DPSK). The nested IQ Modulator structure is capable for the enhanced DQPSK modulation format.

A 40 Gbit Modulator module has been developed with this component. Either GPPO or V-Connectors are used.

Typical bandwidth of such a module is 40 GHz, the necessary driving voltage is Vpp = 2.5 V with an insertion loss of 8 dB.

Lowest drive voltage achieved for a 40 Gbit Modulator was Vpp = 1.5 V.

A variety of different modulators has been developed:

  • MZ Modulator for OOK
  • MZ Modulator for DPSK, Duobinary
  • IQ-Modulator for DQPSK
  • Phase Modulators

All devices are completely fabricated at HHI using our InP processing line. The electro-optic RF-Response can be measured up to 67 GHz on chip and module level.