The Keysight 81195A Optical Modulation Generator is a software-driven signal generation platform that operates with Keysight arbitrary waveform generators to create complex dual-polarization modulated signals and synthesize optical impairments for coherent optical transmission testing. Operating at symbol rates up to 32 GBaud and supporting modulation formats through 256QAM, it enables characterization of 200G, 400G, and 1 Tb/s coherent optical systems.
Technical Specifications
• Signal Generation: Dual-I/Q signal generation for polarization-multiplexed coherent transmission; real-time encoding mode supports up to 32 GBaud with 8 GSym per channel using single M8195A module
• Modulation Capacity: Complex modulated signals up to 256QAM
• M8195A AWG Integration: 65 GSa/s sample rate, 8-bit DAC, up to 16 GSa waveform memory per module, 25 GHz analog bandwidth
• Hardware Support: Primary platform M8195A; legacy waveform generation on M8196A and M8194A
– Key Features
• Real-Time Impairment Adjustment: Signal properties and impairments modified without waveform redownload via hardware DSP block
• Phase Noise Emulation: Artificial phase noise injection simulating laser phase noise, jitter, and frequency offset through IQ pair rotation
• Polarization Control: State-of-polarization (SOP) alteration using concatenated circular and linear retarders with programmable rotation and retardation
• PMD Emulation: Complex FIR butterfly structure replicating optical channel PMD impulse response
• Pulse Shaping: 16-tap programmable FIR filter supporting raised cosine and root-raised cosine filtering
• Non-Linear Equalization: Transfer function approximation using broken-line algorithm
• Dynamic Coefficient Loading: Programmable DSP coefficient memories triggered externally or by dynamic patterns
• Built-In PSK/QAM Encoder: Integrated data pattern symbol encoding
– Typical Applications
Coherent optical system validation, receiver stress testing under channel impairments, modulation format performance characterization, and optical signal integrity assessment across ultra-high-speed transmission networks.
– Compatibility & Integration
Designed as software layer atop Keysight M8195A, M8196A, and M8194A arbitrary waveform generators. Real-time encoding mode (Option RSP) and optical signal property emulation (Option OSP) extend baseline functionality.
