Fiber Optic Attenuator | Fixed & Variable Types for Power Control

Introduction

Opelink manufactures precision fiber optic attenuators for controlling optical power levels in fiber networks. With 13+ years of experience in optical passive components, we provide reliable attenuation solutions to telecom operators, network installers, and test equipment manufacturers worldwide.

A fiber optic attenuator is a passive device that reduces the power level of an optical signal by a predetermined amount, measured in decibels (dB). Attenuators are essential for preventing optical receiver overload, balancing power levels in WDM systems, and simulating fiber loss during network testing.

Opelink offers both fixed attenuators with specific attenuation values (1dB to 30dB) and variable attenuators with adjustable attenuation ranges. Our attenuators feature high precision (±0.5dB accuracy), low return loss, and excellent wavelength independence across 1260-1625nm. All products are manufactured in our ISO 9001:2015 certified facility.

Attenuator Types

Opelink offers various attenuator types to meet different application requirements:

1. Fixed Plug-in Attenuator
Male-to-female design plugs directly into adapter or equipment port. Available in SC, LC, FC, ST types with UPC or APC polish. Fixed attenuation values: 1, 2, 3, 5, 7, 10, 15, 20, 25, 30dB.

2. Fixed Inline Attenuator
In-line design with connectors on both ends. Integrates into patch cord assemblies. Provides fixed attenuation between fiber connections. Available with various connector combinations.

3. Variable Attenuator
Adjustable attenuation using a mechanical mechanism. Allows precise power tuning in the field. Available in inline and bulkhead mount styles. Typical adjustment range: 0-30dB or 0-60dB.

4. Built-in Attenuator
Integrated into active equipment such as transceivers or media converters. Provides fixed attenuation within the device.

Technical Specifications

Parameter	Fixed Attenuator	Variable Attenuator
Attenuation Range	1-30dB (fixed values)	0-30dB or 0-60dB (adjustable)
Attenuation Accuracy	±0.5dB (≤5dB), ±10% (>5dB)	±0.5dB
Return Loss (UPC)	≥50dB	≥45dB
Return Loss (APC)	≥60dB	≥55dB
Operating Wavelength	1260-1625nm	1260-1625nm
Operating Temperature	-40°C to +75°C	-10°C to +60°C
Connector Types	SC, LC, FC, ST	SC, FC
Max Input Power	1W (1000mW)	0.5W (500mW)

Applications

• Receiver Protection: Preventing optical receiver overload from high-power signals
• Power Balancing: Equalizing power levels in DWDM and CWDM systems
• Network Testing: Simulating fiber loss and testing system margins
• BER Testing: Setting precise power levels for bit error rate testing
• CATV Systems: Controlling signal levels in analog and digital video networks
• Laboratory Use: Precise power control in R&D and test environments
• FTTH Networks: Balancing power in PON distribution networks

FAQ

Q1: When should I use an optical attenuator?

A: Use an attenuator when optical power is too high for the receiver, which can cause saturation and bit errors. Common scenarios include: connecting short fibers to high-power transmitters, balancing channels in WDM systems, testing receiver sensitivity, and protecting sensitive equipment from high-power signals.

Q2: What attenuation value do I need?

A: Calculate the required attenuation by subtracting the receiver's optimal input power from the actual received power. For example, if you're receiving -5dBm and your receiver works best at -15dBm, you need approximately 10dB of attenuation. Always leave some margin (1-2dB) for aging and temperature effects.

Q3: What is the difference between fixed and variable attenuators?

A: Fixed attenuators provide a specific, non-adjustable attenuation value (e.g., 10dB). They're simple, reliable, and cost-effective for known requirements. Variable attenuators allow you to adjust the attenuation within a range (e.g., 0-30dB), providing flexibility for changing requirements or precise tuning in test applications.

Q4: Can I use multiple attenuators in series?

A: Yes, attenuators can be cascaded to achieve higher attenuation values. The total attenuation is approximately the sum of individual attenuators (e.g., 5dB + 10dB = ~15dB). However, each connection adds insertion loss and potential reflection points, so using a single higher-value attenuator is preferred when possible.

Q5: Do attenuators work for all wavelengths?

A: Opelink attenuators are designed for wavelength-independent operation across 1260-1625nm, covering all common telecom wavelengths (1310nm, 1490nm, 1550nm, 1625nm). The attenuation value remains consistent across this range, making them suitable for CWDM, DWDM, and broadband applications.