MEMS VOA with Input Power Monitor
(Vibration Insensitive, Directional and Unidirectional)
(patent protection US8666218B2)
Product Overview
The MOAP MEMS Variable Optical Attenuator with Input Optical Power Monitor is a hybrid fiber-optic module. It combines a flat-response thin-film tap and a high-sensitivity InGaAs PIN photodiode with a thermal MEMS VOA. This integration reduces component count, assembly cost, and footprint. The thermal MEMS VOA is designed for minimal temperature dependence and drift, making it suitable for vibration environments such as aircraft and shipping. The monitor path offers low insertion loss and low dark current with excellent temperature stability across the 1260–1620 nm band.
Features
- Integrated Input Power Monitor
- Low Loss Device
- Custom Tap Ratios Available
- Compact Design
Specifications
| Parameter | Min | Typical | Max | Unit |
|---|---|---|---|---|
| Wavelength | 1260 | 1620 | nm | |
| Insertion Loss [1] | 0.6 | 0.8 | dB | |
| Polarization Dependent Loss [2] | 0.15 | 0.8 | dB | |
| Wavelength Dependence Loss[3] | 0.3 | dB | ||
| Attenuation Range | 25 | 35 | dB | |
| Attenuation Resolution | Continuous | |||
| Polarization Mode Dispersion [2] | 0.005 | 0.05 | ps | |
| Return Loss | 38 | dB | ||
| Optical Power [4] | 0.2 | W | ||
| Response Time | 0.2 | 5 | ms | |
| TAP ratio | 1 | 3 | 5 | % |
| Tap Response @ 1550nm | 12 | 15 | 40 | mA/W |
| Wavelength Dependence Response | 0.02 | 0.03 | dB/nm | |
| Polarization Dependence Response [2] | 0.02 | 0.25 | dB | |
| Temperature Dependence Response | 0.01 | dB/°C | ||
| Dark Current at 5V bias @ 23°C | 1 | nA | ||
| 3dB Bandwidth (cutoff frequency) | 10 | MHz | ||
| Capacitance | 6 | pF | ||
| Power Consumption | 130 | 180 | mW | |
| Operating Temperature | -5 | 75 | °C | |
| Storage Temperature | -40 | 85 | °C | |
| Reliability | Telcordia 1209 and 1221 | |||
[1] Without connector and in room temperature.
[2] At attenuation equal or less than 20dB.
[3] At 0dB attenuation and in whole temperature range. Within 30nm Bandwidth.
[4] Requires heat sink at the high input power.
Applications
- Channel Monitoring
- Power Monitoring in Optical Interface Modules
- Gain Monitoring for Amplifier
- DWDM System Monitoring
Mechanical Footprint Dimensions
The mechanical footprint diagram illustrates the physical dimensions and layout of the MEMS VOA module. It shows the main body with dimensions 3.50mm (width) and 23±1mm (length). Input and output fiber ports are indicated. Electrical connections include PD+ and PD- pads for the photodiode and a flexible PCB for VOA control. A reinforcing plate and resistor are also depicted. All dimensions are in millimeters.
Diagram details:
- Main body dimensions: 3.50mm (width), 23±1mm (length).
- Input/Output fibers are present.
- VOA Control Pins (PD+, PD-) are available on a flexible PCB.
- A reinforcing plate (0.1mm thickness) is included.
- Resistor component shown with dimensions 14±1.2mm and 17±0.2mm.
- Other dimensions include 0.80mm, 1.70mm, R0.70, R0.30, and 3.50mm.
*Product dimensions may change without notice. This is sometimes required for non-standard specifications.
Electrical Driving Instruction
Handling and Operating Notes for VOA and Photodiode Connections
- The flexible PCB is for VOA driving. The VOA behaves as a resistive load, has no polarity, and is not sensitive to ESD.
- The maximum control voltage for the VOA is 5 V. ⚠️ Applying a voltage higher than 5 V may damage the device.
- The PD+ and PD- pads are for connecting an external photodiode.
- The Tap photodiode is extremely sensitive to electrostatic discharge (ESD). ⚠️ Even minor ESD damage may not cause immediate failure, but can lead to gradual performance degradation.
- Always short the PD+ and PD- pins together during handling or transport. ✔️
- The black conductive foam covering the photodiode pins must not be removed until final assembly in an ESD-safe environment.
Ordering Information
| Prefix | Tap Ratio | Wavelength | VOA Off State | Directivity | Fiber Type | Fiber Cover | Fiber Length | Connector |
|---|---|---|---|---|---|---|---|---|
| MOAP- | 3% = 03 Special = 00 |
C+L = 2 1310 = 3 1550 = 5 1260-1620 = B Special = 0 |
Transparent = 1 Opaque = 2 |
No = 1 Yes = 2 |
SMF-28 = 1 PM1550 = 2 Special = 0 |
Bare fiber = 1 900um tube = 3 Special = 0 |
0.25m = 1 0.5m = 2 1.0m = 3 Special = 0 |
None = 1 FC/PC = 2 FC/APC = 3 SC/PC = 4 SC/APC = 5 ST/PC = 6 LC/PC = 7 LC/APC = 8 Special = 0 |
Note: "transparent" means no attenuation without applying a controlling voltage, the "opaque" means the highest attenuation without applying a controlling voltage.
Performance Graphs
Typical Insertion Loss vs Wavelength (1240-1630nm)
The 'Typical Insertion Loss vs Wavelength' graph displays the optical performance of the MEMS VOA. The X-axis represents Wavelength (nm) from 1240 to 1590, and the Y-axis represents Signal (dB) from -4 to 3. The plotted line shows that the insertion loss is consistently low and flat across the entire 1240-1630nm range, typically around 0 dB with minimal variation.
Response 0~20dB
The 'Response 0~20dB' graph captures the dynamic response of the VOA. It shows two channels: Channel 1 (likely the control signal) and Channel 2 (the optical output response). Channel 1 exhibits a square wave pattern, indicating the activation and deactivation of the attenuation. Channel 2 mirrors this pattern with a corresponding optical output change, demonstrating the device's response speed. The time scale is set to 10.0ms per division.
