Comprehensive analysis of optical module: detailed explanation of functions, types and application

Optical module is a key optical fibre communication device, its main function is to convert electrical signals into optical signals and transmit data through optical fibre media.

Classification of Optical Module: Distinguished according to function, package form, transmission rate, wavelength, interface type, operating temperature and transmission distance.

1. Functional classification:

Optical Transmitter Module (TOSA): Converts electrical signals into optical signals and transmits them into optical fibres. The optical signal will be

Optical Receiver Module (ROSA): Converts optical signals into electrical signals for signal reception and processing.

2. Package classification:

GBIC: Earlier form of packaging, larger size.

SFP: small pluggable module, widely used in a variety of network equipment.

SFP+: Upgraded version of SFP, supports higher transmission rates.

SFP28: Supports 25Gbps rate, same size as SFP+.

QSFP+: Supports 40Gbps rate, suitable for high-density network connection.

QSFP28: Supports 100Gbps rate, suitable for ultra-high speed data transmission.

QSFP56: Supports 200Gbps rate, suitable for data centre, AI, cloud computing.

OSFP: Supports 200Gbps rate, applied to Ethernet, AI, cloud server.

OSFP-DD: Support 800Gbps rate, applied to AI, cloud computing, big data analysis.

Electrical interface module: using RJ45 interface, the transmission medium is copper wire.

3. Rate classification:

100Mbps

Gigabit (1Gbps)

2.5Gbps

10Gbps

25Gbps

40Gbps

100Gbps

200Gbps

400Gbps

800Gbps

4. Wavelength classification:

850nm, 1310nm, 1550nm, CWDM (1270~1610nm), DWDM (1525~1565nm or 1570~1610nm) and so on

5.Interface classification:

1.Optical interface module (fibre optic interface):

Transmission medium: optical fibre

Interface type: LC, MTP/MPO, etc.

Transmission mode: optical signals

2. Electrical interface module (RJ45 interface):

Transmission medium: network cable (copper)

Interface type: RJ45

Transmission mode: electrical signal

6.Working temperature:

Optical modules can be divided into according to the temperature requirements of the working environment:

• • Commercial grade (0-70℃)
  • Extended grade (-20-85℃)
  • Industrial grade (-40-85 ℃)

7.Transmission distance:

Short distance: usually refers to the transmission distance within a few hundred metres, applicable to the connection within the data centre or local area network (LAN) connection. Multimode fibre is usually used for short distance transmission, and the transmission rate can reach several Gbps to tens of Gbps.

Medium Distance: Typically refers to transmission distances of a few kilometres to more than ten kilometres and is suitable for Metropolitan Area Network (MAN) connections or connections between data centres. Single-mode fibre is typically used for medium-distance transmission and can reach transmission rates of a few Gbps to tens of Gbps.

Long-haul: Typically refers to transmission distances of tens to hundreds of kilometres and is suitable for Wide Area Network (WAN) connections or data transmission across longer distances. Single-mode fibre is typically used for long-haul transmissions, where transmission rates can reach several Gbps to tens of Gbps and beyond.

Ultra-long-haul: refers to transmission distances of more than hundreds or even thousands of kilometres, and is usually used for long-distance transmission in optical communication networks. In ultra-long distance transmission, optical amplifiers and other signal processing techniques are usually required to enhance the signal and compensate for signal attenuation.