The terms OS1, OS2, OM1, OM2, OM3, and OM4 refer to different types of optical fibers used in fiber optic cabling, each with specific characteristics. These designations are part of the industry standards that define the performance and specifications of optical fibers. Here's what each term represents:

1. OS1 (Optical Single-Mode 1):

• Description: OS1 is a designation for single-mode optical fiber with standard performance characteristics.

• Application: Used for long-distance transmissions and applications that require a narrow, single-mode beam of light.

• Typical Use: Telecommunications, high-speed data applications over long distances.

2. OS2 (Optical Single-Mode 2):

• Description: OS2 is a designation for single-mode optical fiber with enhanced performance characteristics, often used in longer-distance applications.

• Application: Used for telecommunications and high-speed data applications where low signal loss is critical.

• Typical Use: Long-distance connections, metropolitan area networks (MANs), and other applications requiring high bandwidth.

3. OM1 (Optical Multimode 1):

• Description: OM1 is a designation for multimode optical fiber with standard performance characteristics.

• Core Diameter: 62.5 micrometers

• Application: Used for short-distance transmissions and applications in local area networks (LANs).

• Typical Use: Ethernet, especially in older installations.

4. OM2 (Optical Multimode 2):

• Description: OM2 is a designation for multimode optical fiber with slightly better performance than OM1.

• Core Diameter: 50 micrometers

• Application: Used for short-distance transmissions in LANs.

• Typical Use: Ethernet, especially in older installations.

5. OM3 (Optical Multimode 3):

• Description: OM3 is a designation for multimode optical fiber with enhanced performance characteristics, specifically designed for higher bandwidth.

• Core Diameter: 50 micrometers

• Application: Used for higher-speed data transmissions, such as 10 Gigabit Ethernet, 40 Gigabit Ethernet, and 100 Gigabit Ethernet over short distances.

• Typical Use: Data centers, high-performance computing environments.

6. OM4 (Optical Multimode 4):

• Description: OM4 is a designation for multimode optical fiber with even better performance than OM3, designed to support higher data rates over longer distances.

• Core Diameter: 50 micrometers

• Application: Used for high-speed data transmissions, including 10 Gigabit Ethernet, 40 Gigabit Ethernet, and 100 Gigabit Ethernet, with increased reach compared to OM3.

• Typical Use: Data centers, high-performance computing environments.

These designations help users select the appropriate type of optical fiber based on their specific requirements for data rate, distance, and application. The choice of fiber type depends on factors such as the network architecture, transmission distance, and the technology used in the networking equipment.