The **SVB-2DW-R/Q** refers to a high-performance, dual-window (bi-directional) optical sub-assembly, typically used in fiber optic communication systems. Specifically, it is a component of a **BOSA (Bi-Directional Optical Sub-Assembly)** used in GPON/EPON networks. --- ### 1. General Specifications This part is designed to transmit and receive signals over a single fiber strand by using different wavelengths. | Feature | Description | | :--- | :--- | | **Component Type** | BOSA (Bi-Directional Optical Sub-Assembly) | | **Fiber Type** | Single-Mode Fiber (SMF) | | **Configuration** | 2-DW (Dual Window / Diode Window) | | **Connector Type** | Usually SC/UPC or SC/APC (Pigtail or Receptacle) | | **Key Functions** | Laser Diode (Transmitter) + Photodiode (Receiver) | --- ### 2. Internal Electronic Components The "R/Q" designation usually points to specific internal configurations regarding the Transimpedance Amplifier (TIA) and the Laser Diode type. #### A. Transmitter Section (Tx) * **Laser Diode (LD):** Typically a 1310nm DFB (Distributed Feedback) or FP (Fabry-Perot) laser. * **Monitor Photodiode (MPD):** Integrated to provide feedback to the laser driver to maintain constant optical output power (APC - Automatic Power Control). #### B. Receiver Section (Rx) * **Photodiode (PD):** Typically a 1490nm or 1550nm InGaAs PIN photodiode. * **Transimpedance Amplifier (TIA):** A high-gain electronic chip that converts the weak current from the photodiode into a differential voltage signal for the processing chip. * **WDM Filter:** An internal optical filter that separates the incoming and outgoing wavelengths so they do not interfere. --- ### 3. Pinout Logic (Typical 2-DW/Q Layout) Most SVB-series components use a multi-pin header (often 5 to 9 pins). | Pin Category | Function | | :--- | :--- | | **LD Anode/Cathode** | Connections to drive the laser transmitter. | | **PD Anode/Cathode** | Connections for the receiving photodiode. | | **Vcc / GND** | Power supply (usually 3.3V) and Ground for the internal TIA. | | **Monitor PD** | Pins for sensing the output power of the laser. | --- ### 4. Application Context The **SVB-2DW-R/Q** is commonly found in: 1. **ONU/ONT Devices:** The "modem" inside a customer's home for fiber internet. 2. **FTTH Networks:** Fiber-to-the-home deployments. 3. **Media Converters:** Converting optical signals to electrical Ethernet signals. ---