Rof Electro-optic modulator Ultra Compact DP-IQ Modulator Automatic Bias Controller

Ultra-Compact DP-IQ Modulator Bias Controller

Introduction

            A DP-IQ modulator consists of two IQ modulators and a polarization rotator. Each IQ modulator consists of three different modulators: I, Q arms are intensity modulators, Parm is a phase modulator. The DP-IQ modulator is typically applied to DP- QPSK systems. Rofea's modulator bias controller is specially designed for DP- IQ modulators to ensure stable operations in various operating environments. Based on its entirely digitized signal processing method, the controller can provide ultra-stable performance.

        The controller injects a low frequency, low amplitude dither signal, and a bias voltage into the modulator. It keeps reading the modulator's output and determines the condition of the modulator and the related error. A compensate bias voltage will be applied afterward according to the previous measurements. In this way, the DP-IQ modulator is ensured to work under a proper bias voltage.

Feature

1. Simultaneously provides six automatic bias voltages for Dual Polarization IQ modulators
2.Modulation format-independent:
a. SSB, QPSK, QAM, OFDM verified.
3. Plug and Play:
a. No manual calibration needed Everything automatic
b. I, Q arms: control on Peak and Null modes High extinction ratio:50dB max1
• Parm: control on Q+ and Q- modes Accuracy: ± 2^◦
• Low profile: 40mm(W) × 29mm(D) × 8mm(H)
• High stability: fully digital implementation Easy to use:
4. Manual operation with a mini jumper
5. Flexible OEM operations through UART2 /IO
6. Two modes to provide bias voltages: a.Automatic Bias Control b.User-defined bias voltage

Application

• LiNbO3 and other DP-IQ modulators
• Coherent Transmission
1 The highest extinction ratio depends on and cannot exceed one system modulator maximum extinction ratio.
2 UART operation is only available on some versions of the controller.