TOSLINK (from ''Toshiba Link'') is a standardized

optical fiber connector An optical fiber connector joins optical fibers, and enables quicker connection and disconnection than splicing. The connectors mechanically couple and align the cores of fibers so light can pass. Better connectors lose very little light due ...

system. Also known generically as optical audio, its most common use is in consumer

audio Audio most commonly refers to sound, as it is transmitted in signal form. It may also refer to: Sound *Audio signal, an electrical representation of sound *Audio frequency, a frequency in the audio spectrum * Digital audio, representation of sou ...

equipment (via a "digital optical" socket), where it carries a

digital audio Digital audio is a representation of sound recorded in, or converted into, digital form. In digital audio, the sound wave of the audio signal is typically encoded as numerical samples in a continuous sequence. For example, in CD audio, samp ...

stream from components such as CD and DVD players, Digital Audio Tape recorders, computers, and modern

video game console A video game console is an electronic device that outputs a video signal or image to display a video game that can be played with a game controller. These may be home consoles, which are generally placed in a permanent location connected to ...

s, to an

AV receiver An audio/video receiver (AVR) is a consumer electronics component used in a home theater. Its purpose is to receive audio and video signals from a number of sources, and to process them and provide power amplifiers to drive loudspeakers and ro ...

that can decode two channels of uncompressed lossless

pulse-code modulated Pulse-code modulation (PCM) is a method used to digitally represent sampled analog signals. It is the standard form of digital audio in computers, compact discs, digital telephony and other digital audio applications. In a PCM stream, the amp ...

(PCM) audio or

surround sound Surround sound is a technique for enriching the fidelity and depth of sound reproduction by using multiple audio channels from speakers that surround the listener (surround channels). Its first application was in movie theaters. Prior to s ...

such as

Dolby Digital Dolby Digital, originally synonymous with Dolby AC-3, is the name for what has now become a family of audio compression technologies developed by Dolby Laboratories. Formerly named Dolby Stereo Digital until 1995, the audio compression is loss ...

or DTS Surround System. Unlike

HDMI High-Definition Multimedia Interface (HDMI) is a proprietary audio/video interface for transmitting uncompressed video data and compressed or uncompressed digital audio data from an HDMI-compliant source device, such as a display controlle ...

, TOSLINK does not have the bandwidth to carry the lossless versions of

Dolby TrueHD Dolby TrueHD is a lossless, multi-channel audio codec developed by Dolby Laboratories for home video, used principally in Blu-ray Disc and compatible hardware. Dolby TrueHD, along with Dolby Digital Plus (E-AC-3) and Dolby AC-4, is one of the i ...

DTS-HD Master Audio DTS-HD Master Audio (DTS-HD MA; known as DTS++ before 2004) is a multi-channel, lossless audio codec developed by DTS as an extension of the lossy DTS Coherent Acoustics codec (DTS CA; usually itself referred to as just DTS). Rather than being ...

, or more than two channels of PCM audio. Although TOSLINK supports several different media formats and physical standards, digital audio connections using the rectangular

EIAJ Founded in 1948, the Electronic Industries Association of Japan (EIAJ) was one of two Japanese electronics trade organizations that were merged into the Japan Electronics and Information Technology Industries Association (JEITA). Prior to the me ...

JEITA The is a Japanese trade organization for the electronics and IT industries. It was formed in 2000 from two earlier organizations, the Electronic Industries Association of Japan and the Japan Electronic Industries Development Association. Histor ...

RC-5720 (also CP-1201 and JIS C5974-1993 F05) connector are by far the most common. 100621 digikey.com The optical signal is a red light with a peak wavelength of Depending on the type of modulated signal being carried, other optical wavelengths may be present.

History

Toshiba , commonly known as Toshiba and stylized as TOSHIBA, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. Its diversified products and services include power, industrial and social infrastructure systems, ...

originally created TOSLINK to connect their CD players to the receivers they manufactured, for

PCM Pulse-code modulation (PCM) is a method used to digitally represent sampled analog signals. It is the standard form of digital audio in computers, compact discs, digital telephony and other digital audio applications. In a PCM stream, the am ...

audio streams. The software layer is based on the "Sony/Philips Digital Interface" (

S/PDIF S/PDIF (Sony/Philips Digital Interface) is a type of digital audio interface used in consumer audio equipment to output audio over relatively short distances. The signal is transmitted over either a coaxial cable (using RCA or BNC connectors ...

), while the hardware layer utilizes a fiber optic transmission system, rather than the electrical (copper) hardware layer of S/PDIF. TOSLINK was soon adopted by manufacturers of most CD players. It can often be found on video source (DVD and Blu-ray players, cable boxes and game consoles) to connect the digital audio stream to

/ DTS decoders. The name is a registered trademark of Toshiba, created from ''TOShiba-LINK''. Variations of the name, such as ''TOSlink'', ''TosLink'', and ''Tos-link'', are also seen, while the official generic name for the standard is ''EIAJ optical''.

ADAT Lightpipe The ADAT Lightpipe, officially the ADAT Optical Interface, is a standard for the transfer of digital audio between equipment. It was originally developed by Alesis but has since become widely accepted, with many third party hardware manufacturers ...

or simply ADAT Optical uses an optical transmission system similar to TOSLINK, and is used in the professional music/audio industry. While the ADAT Lightpipe format uses the same JIS F05 connectors as TOSLINK, the ADAT Lightpipe data format is not compatible with S/PDIF.

Properties and issues

Due to their high attenuation of light, the effective range of plastic optical cables is limited to . They can temporarily fail or be permanently damaged if tightly bent. Although less commonly available and more expensive than plastic optical fiber (POF) cables, glass or silica optical fibers have lower losses and can extend the range of the TOSLINK system. Optical cables are not susceptible to electrical problems such as ground loops and RF interference.

Design

Several types of fiber can be used for TOSLINK: inexpensive plastic optical fiber, higher-quality multistrand plastic optical fibers, or quartz glass optical fibers, depending on the desired bandwidth and application. TOSLINK cables are usually limited to in length, with a technical maximum of , for reliable transmission without the use of a signal booster or a repeater. However, it is very common for interfaces on newer consumer electronics (satellite receivers and PCs with optical outputs) to easily run over on even low-cost TOSLINK cables. TOSLINK transmitters operate at a nominal optical wavelength of .

Mini-TOSLINK

Mini-TOSLINK is a standardized

smaller than the standard square TOSLINK connector commonly used in larger consumer

equipment. The plug is almost the same size and shape as the ubiquitous stereo minijack. Adapters are available to connect a full-size TOSLINK plug to a mini-TOSLINK socket. Combined jack and mini-TOSLINK sockets exist which can accept a jack or a mini-TOSLINK plug; mini-TOSLINK plugs are made longer than electrical jack plugs so that the latter are too short to touch and damage the LED of combined connectors. Many discontinued

laptop computer A laptop, laptop computer, or notebook computer is a small, portable personal computer (PC) with a screen and alphanumeric keyboard. Laptops typically have a clam shell form factor with the screen mounted on the inside of the upper li ...

and portable digital audio equipment models, such as the Google Chromecast Audio device,

Apple An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple trees are cultivated worldwide and are the most widely grown species in the genus '' Malus''. The tree originated in Central Asia, where its wild ancest ...

AirPort Express The AirPort Express is a Wi-Fi base station product from Apple Inc., part of the AirPort product line. While more compact and in some ways simpler than another Apple Wi-Fi base station, the AirPort Extreme, the Express offers audio output cap ...

, and

iPod Hi-Fi iPod Hi-Fi is a discontinued speaker system that was developed and manufactured by Apple Inc. and was released on February 28, 2006, for use with any iPod digital music player. The iPod Hi-Fi retailed at the Apple Store for US$ The Unit ...

use these connectors that allow for the insertion of analog (electrical) headphone output, microphone input, or mini-TOSLINK digital (optical) output.

References

External links

TOSLINK Interconnect History & Basics
{{DEFAULTSORT:Toslink Audiovisual introductions in 1983 Consumer electronics Fiber-optic connectors Toshiba brands Japanese inventions Digital audio transport Optical communication interfaces Digital audio connectors