Based on available industry data, the part number **M5R85XQJ-R** corresponds to a specific high-performance **Vertical-Cavity Surface-Emitting Laser (VCSEL)** diode, typically manufactured by companies like Finisar (now part of II-VI/Coherent). These components are critical in high-speed fiber optic communications. --- ### ## Technical Specifications Below is a breakdown of the primary electronic and optical characteristics of the M5R85XQJ-R: | Feature | Specification | Description | | :--- | :--- | :--- | | **Type** | VCSEL Diode | Vertical-Cavity Surface-Emitting Laser | | **Wavelength** | 850 nm | Standard for Multi-Mode Fiber (MMF) | | **Data Rate** | Up to 10 - 25 Gbps | Used in high-speed Ethernet and Fibre Channel | | **Package** | Die / TO-Can / SMT | Often sold as a bare die for integration into Transceivers | | **Material** | GaAs | Gallium Arsenide-based semiconductor | | **Configuration** | Common Anode/Cathode | Depends on the specific array or single-channel build | --- ### ## Key Electronic Features 1. **High-Speed Modulation**: Designed for high-bandwidth applications, the component supports low-threshold currents and high-slope efficiency, allowing it to toggle between 0 and 1 states at nanosecond speeds. 2. **Low Power Consumption**: Unlike edge-emitting lasers, VCSELs like the M5R85XQJ-R require significantly less drive current, reducing the thermal footprint of the optical module. 3. **Beam Characteristics**: The "Vertical-Cavity" design produces a circular beam with low divergence. Electronically, this simplifies the coupling to the fiber optic cable, as it requires less complex lenses than traditional lasers. 4. **Reliability (R-Suffix)**: The "R" at the end of the part number often denotes **Tape and Reel** packaging or a specific **RoHS compliance** rating for industrial manufacturing. --- ### ## Common Applications This part is a building block for the following hardware: * **SFP+ / QSFP+ Transceivers**: The optical engine inside modules used in data center switches. * **Active Optical Cables (AOC)**: High-speed cables with integrated electronics at the ends. * **Optical Sensors**: High-resolution proximity or 3D sensing (LiDAR) in specific industrial contexts. --- ### ## Operational Circuit Example When integrating this part into a circuit, a laser driver IC is required to manage the bias current and modulation. ```cpp // Logic representation of VCSEL Driver Control void adjustLaserPower(float target_mw) { float bias_current = calculate_bias(target_mw); float mod_current = calculate_modulation(DATA_RATE_GBPS); // Set DAC values for the Laser Driver IC DAC_Write(CHANNEL_BIAS, bias_current); DAC_Write(CHANNEL_MOD, mod_current); } ```