Coreray: Leading Fiber Optic Switch Manufacturer - MEMS & Mechanical Optical Solutions

Introduction

    In modern photonic systems, controlling optical power is as critical as generating or detecting light. Whether in DWDM channel balancing, sensor array readout, or automated test equipment, the ability to independently adjust the power of multiple optical signals with high accuracy directly impacts system performance. Traditionally, this required stacking multiple single‑channel variable optical attenuators (VOAs), consuming space, cost, and power. Enter the MEMS variable attenuator array—a compact, integrated solution that packs multiple VOAs into one module.

    This article explores the technology behind MEMS VOA arrays, their advantages over discrete solutions, key application areas, and how to select the right array for your project.

MEMS Technology in a Nutshell

    Micro‑Electro‑Mechanical Systems (MEMS) refer to tiny mechanical structures fabricated on silicon substrates using semiconductor processes. In a MEMS VOA, an electrostatic actuator tilts a micromirror to divert a portion of the light away from the output fiber, thereby attenuating the signal. The control voltage (typically 0–5V) determines the mirror angle and hence the attenuation level.

MEMS VOAs offer several benefits:

·         Low power consumption – Electrostatic actuation consumes almost no steady‑state current.

·         High speed – Response times in the millisecond range, suitable for dynamic control.

·         Excellent repeatability – No mechanical wear, ensuring consistent performance over millions of cycles.

·         Compact size – Multiple channels can be integrated on a single chip.

Why an Array?

Many applications require simultaneous control of numerous optical channels. Examples include:

·         DWDM systems where each wavelength channel needs independent power equalization.

·         Fiber sensor arrays (e.g., FBG interrogators) that sequentially address multiple sensing points.

·         Multi‑channel optical test sets that must apply different attenuation levels to each channel under test.

Using an array of MEMS VOAs offers distinct advantages over discrete components:

·         Space saving – A 16‑channel array occupies a fraction of the board space needed for 16 separate VOAs.

·         Simplified wiring – One multi‑pin connector replaces 16 individual control lines (plus grounds).

·         Cost efficiency – Shared housing, electronics, and assembly reduce per‑channel cost.

·         Consistent performance – Channels are matched in terms of loss, PDL, and wavelength response.

Inside the Coreray MEMS VOA Array

Coreray’s VOAM series integrates up to 16 independent VOAs in a compact module. Each channel offers:

·         Wavelength range 400–2640nm – covers visible to near‑IR, including telecom bands.

·         Attenuation range up to 55dB with 0.1dB resolution.

·         Insertion loss as low as 0.6dB (typical) without connectors.

·         Low PDL ≤0.2dB for SM fibers over 0–15dB attenuation.

·         High return loss >50dB for SM/PM, >35dB for MM.

·         Fast response 1–3ms (0→20dB).

The module supports various fiber types (SMF‑28, HI1060, PM fibers, multimode) and connector options (FC, SC, LC, etc.), ensuring compatibility with existing setups. The 0–5V analog control interface simplifies integration with DACs, microcontrollers, or PLC systems.

Application Spotlight: Automated Test Equipment

    In an optical component production line, a typical test setup might include a tunable laser, a power meter, and a switch to cycle through multiple devices. By placing a MEMS VOA array between the source and the device under test, engineers can simulate different attenuation scenarios (e.g., fiber link loss) without manual intervention. The fast response time allows rapid sweeping of attenuation levels, while the high repeatability ensures consistent test results.

Comparison: MEMS vs. Other VOA Technologies

For multi‑channel applications requiring a balance of speed, accuracy, and size, MEMS arrays are often the optimal choice.

Selecting the Right VOA Array

When choosing a variable optical attenuator array, consider:

1.    Number of channels – How many independent attenuators do you need? Coreray offers 9‑ to 16‑channel options.

2.    Wavelength range – Ensure the module covers your operating wavelengths.

3.    Fiber type – Single‑mode, multimode, or polarization‑maintaining? The choice affects loss and PDL.

4.    Attenuation range and resolution – Do you need up to 55dB, or is 40dB sufficient? 0.1dB resolution is standard.

5.    Package and connectors – Module size and fiber terminations must match your system.

6.    Control interface – Analog voltage (0–5V) is simple; some applications may require digital control (I²C, SPI) – custom options are available.

Conclusion

    MEMS variable attenuator arrays are a powerful tool for modern optical system designers, offering compact, cost‑effective, and high‑performance power control across multiple channels. Coreray’s VOAM series exemplifies this technology, providing flexibility, reliability, and ease of integration. Whether you’re building a DWDM test system, a multi‑channel sensor interrogator, or any application requiring precise optical attenuation, a MEMS VOA array from Coreray can streamline your design and reduce costs.

For more information or to request a custom configuration, visit www.coreray.com or contact our engineering team.