IOR (Index Of Refraction)

The ratio between the velocity of light in a vacuum to the velocity of

light in a transmission medium, such as a given type of glass. Refraction refers to the phenomenon by which light changes velocity and changes direction (i.e., bends or refracts) as it exits one medium and enters another of different density.The IOR is mathematically expressed as

n = c ÷ v

where c is the velocity of light in a vacuum, and v is the speed of light in the given medium. So, IOR is the mathematical inverse of velocity of propagation (Vp). IOR is a convenient means for expressing the differences between the speed of light in different types of optical fiber, as well as between the core and cladding of a glass optical fiber (GOF).Table I-2 provides approximate IOR comparisons of various substances.

• Simple Gateway Control Protocol (SGCP)
• Simple Mail Transfer Protocol (SMTP)
• simple mode
• Simple Network Management Protocol (SNMP)
• SIMPLE (Session Initiation Protocol [SIP] for Instant Messaging and Presence Leveraging
• simplex
• simplex
• simplex
• simplified message desk interface (SMDI)
• SIM (Subscriber Identification Module)
• sine wave
• Single-Ended Method for Objective Speech Quality Assessment in Narrow-Band Telephony
• single-key encryption
• single-line digital subscriber line (SDSL)
• single-line DSL (SDSL)
• single-mode fiber (SMF)
• single number dialing
• single number dialing
• single number dialing
• Single Point of Termination (SPOT)
• single sideband (SS or SSB)
• sink
• S interface
• sintering
• sinusoidal waveform