Yes, OM3 (Optical Multimode 3) fiber optic cabling is capable of supporting 40 Gigabit Ethernet (40GbE) connections. OM3 is a type of multimode fiber (MMF) commonly used in data center and enterprise environments for high-speed networking applications. The key features of OM3 fiber that make it suitable for 40GbE include:

1. Bandwidth: OM3 fiber has higher bandwidth compared to its predecessor, OM2. The increased bandwidth allows it to support higher data rates, including 40GbE.

2. Core Diameter: OM3 fiber typically has a core diameter of 50 micrometers, similar to OM2. The larger core diameter facilitates the transmission of multiple modes of light, making it a multimode fiber.

3. Modal Bandwidth: OM3 has a higher modal bandwidth than OM2, which contributes to its ability to support higher data rates over short distances.

4. Wavelength: OM3 fiber is optimized for use with vertical-cavity surface-emitting lasers (VCSELs) operating at a wavelength of 850 nanometers (nm), which is commonly used in short-range fiber optic transmissions.

When deploying 40GbE connections over OM3 fiber, it's essential to consider the reach limitations associated with multimode fiber. Typically, OM3 is suitable for relatively short-distance applications within a data center or between closely located data center facilities. The maximum reach for 40GbE over OM3 is often around 100 meters using parallel optics (e.g., QSFP+ SR4 or QSFP28 SR4 transceivers).

It's important to note that if longer reach is required, single-mode fiber (SMF) or other multimode fibers with higher performance, such as OM4 or OM5, may be considered. Always refer to the specific standards and recommendations provided by the equipment manufacturers and industry standards bodies for accurate information on fiber compatibility and reach.