What are the common types of optical modules
Classification by rate
In order to meet the demand of various transmission rates, optical modules of different rates are produced: 400GE optical module, 100GE optical module, 40GE optical module, 25GE optical module, 10GE optical module, GE optical module, FE optical module, etc.
Classification by encapsulation type
The higher the transmission rate, the more complex the structure, resulting in different encapsulation types. The encapsulation types applicable to Huawei switches are: QSFP-DD, QSFP28, QSFP+, SFP28, SFP/eSFP, SFP+, CXP, CFP, etc.
封装类型 | 基本解释 | 外观图 |
|---|---|---|
SFP/eSFP光模块 | SFP（Small Form-factor Pluggable）光模块：小型可插拔。SFP光模块支持LC光纤连接器。 eSFP（Enhanced Small Form-factor Pluggable）光模块：增强型SFP，指的是带电压、温度、偏置电流、发送光功率、接收光功率监控功能的SFP，当前所有的SFP都带，所以也就把eSFP都统一叫SFP了。 | |
SFP+光模块 | SFP+（Small Form-factor Pluggable Plus）光模块：指速率提升的SFP模块，因为速率提升，所以对EMI敏感，壳子上面的裙片做的多了，配对的笼子也相对缩紧了。 | |
SFP28光模块 | SFP28（Small Form-factor Pluggable 28）光模块：接口封装大小与SFP+相同，支持速率为25G的SFP28光模块和10G的SFP+光模块。 | |
QSFP+光模块 | QSFP+（Quad Small Form-factor Pluggable）光模块：四通道小型可热插拔光模块。QSFP+光模块支持MPO光纤连接器，相比SFP+光模块尺寸更大。 | |
CXP光模块 | CXP（120 Gb/s eXtended-capability Form Factor Pluggable Module）光模块：是一种可热插拔的高密并行光模块标准，在发送和接收（Tx/Rx）方向各提供12个通道，仅适用于短距离多模链路。 | |
CFP光模块 | CFP（Centum Form-factor Pluggable）光模块：长×宽×高尺寸定义为144.75mm×82mm×13.6mm，是一种高速的可以热插拔的支持数据通信和电信传输两大应用的新型光模块标准。 | |
QSFP28光模块 | QSFP28（Quad Small Form-factor Pluggable 28）光模块：接口封装大小与QSFP+相同，支持速率为100G的QSFP28光模块和40G的QSFP+光模块。 | |
QSFP-DD光模块 | QSFP-DD（(Quad Small Form Factor Pluggable-Double Density)）光模块：双密度四通道小型可插拔封装光模块，是QSFP-DD MSA小组定义的一种高速可插拔模块。 |
Classification by mode
Optical fiber is divided into single-mode optical fiber, multimode optical fiber. In order to use different categories of optical fiber, single-mode optical modules, multi-mode optical modules are produced.
The center wavelength of single-mode optical module is generally 1310nm, 1550nm, which is used with single-mode fiber. Single-mode optical fiber has wide transmission band and large transmission capacity, which is suitable for long distance transmission.
The center wavelength of multimode optical module is generally 850nm, which is used with multimode fiber. Multimode fiber has mode dispersion defects, its transmission performance is worse than single-mode fiber, but the cost is low, suitable for smaller capacity, short-distance transmission.
Using long-range optical modules, the transmit optical power is generally greater than the overload optical power, so you need to pay attention to the fiber length to ensure that the actual received optical power is less than the overload optical power. If the fiber length is short, the use of long-range optical modules need to be used with fiber optical attenuation (fiber attenuation value per unit length in dB/km) to avoid burning the opposite end of the optical module.
Classification by central wavelength
The operating wavelength of an optical module is a range, and the parameter of central wavelength is used for the convenience of description, and the unit is nanometer (nm).
In order to support optical signal transmission using different optical wavelengths, optical modules with different central wavelengths are produced, such as: 850nm, 1310nm, 1550nm optical modules, etc.
Classification by color
The biggest difference between color optical modules and other types of optical modules is that the central wavelength is different.
The center wavelength of general optical modules are 850nm, 1310nm and 1550nm, the center wavelength is relatively single, we call this type of light "black and white light" or "gray light".
Color light module carries a number of different central wavelengths of light, so the intersection is colorful, we call this type of light for "color light".
Color light module is divided into two kinds of coarse set wave optical module (CWDM) and dense wave optical module (DWDM). In the same wavelength, there are more types of dense wavelength modules, so dense wavelength modules use the resources of the wavelength more fully. Light with different center wavelengths can be transmitted in the same fiber without interfering with each other, so the light from multiple color optical modules with different center wavelengths is combined into one way for transmission by passive combiner, and the remote end is divided into multiple ways according to different center wavelengths by splitter, which effectively saves fiber optic lines. Color optical modules are mainly used in long distance transmission lines.
Classification examples
According to the classification introduced above, the following are some examples of common optical module classifications.
Type | SFP-GE-LH40-SM1310 | SFP-10G-ER-1310 | QSFP-40G-LR4 | QSFP-100G-CWDM4 | QSFP-DD-400G-SR8 | |
|---|---|---|---|---|---|---|
Speed | GE | 10GE | 100GE | 400GE | ||
Package type | eSFP | SFP+ | QSFP28 | QSFP-DD | ||
Mode | Single-mode | Single-mode | Single-mode | Multimode | ||
Central wavelength（nm） | 1310 | 1310 | Black and white light | Black and white light | Color |
What are the common types of optical modules
Classification by rate
In order to meet the demand of various transmission rates, optical modules of different rates are produced: 400GE optical module, 100GE optical module, 40GE optical module, 25GE optical module, 10GE optical module, GE optical module, FE optical module, etc.
Classification by encapsulation type
The higher the transmission rate, the more complex the structure, resulting in different encapsulation types. The encapsulation types applicable to Huawei switches are: QSFP-DD, QSFP28, QSFP+, SFP28, SFP/eSFP, SFP+, CXP, CFP, etc.
封装类型 | 基本解释 | 外观图 |
|---|---|---|
SFP/eSFP光模块 | SFP（Small Form-factor Pluggable）光模块：小型可插拔。SFP光模块支持LC光纤连接器。 eSFP（Enhanced Small Form-factor Pluggable）光模块：增强型SFP，指的是带电压、温度、偏置电流、发送光功率、接收光功率监控功能的SFP，当前所有的SFP都带，所以也就把eSFP都统一叫SFP了。 | |
SFP+光模块 | SFP+（Small Form-factor Pluggable Plus）光模块：指速率提升的SFP模块，因为速率提升，所以对EMI敏感，壳子上面的裙片做的多了，配对的笼子也相对缩紧了。 | |
SFP28光模块 | SFP28（Small Form-factor Pluggable 28）光模块：接口封装大小与SFP+相同，支持速率为25G的SFP28光模块和10G的SFP+光模块。 | |
QSFP+光模块 | QSFP+（Quad Small Form-factor Pluggable）光模块：四通道小型可热插拔光模块。QSFP+光模块支持MPO光纤连接器，相比SFP+光模块尺寸更大。 | |
CXP光模块 | CXP（120 Gb/s eXtended-capability Form Factor Pluggable Module）光模块：是一种可热插拔的高密并行光模块标准，在发送和接收（Tx/Rx）方向各提供12个通道，仅适用于短距离多模链路。 | |
CFP光模块 | CFP（Centum Form-factor Pluggable）光模块：长×宽×高尺寸定义为144.75mm×82mm×13.6mm，是一种高速的可以热插拔的支持数据通信和电信传输两大应用的新型光模块标准。 | |
QSFP28光模块 | QSFP28（Quad Small Form-factor Pluggable 28）光模块：接口封装大小与QSFP+相同，支持速率为100G的QSFP28光模块和40G的QSFP+光模块。 | |
QSFP-DD光模块 | QSFP-DD（(Quad Small Form Factor Pluggable-Double Density)）光模块：双密度四通道小型可插拔封装光模块，是QSFP-DD MSA小组定义的一种高速可插拔模块。 |
Classification by mode
Optical fiber is divided into single-mode optical fiber, multimode optical fiber. In order to use different categories of optical fiber, single-mode optical modules, multi-mode optical modules are produced.
The center wavelength of single-mode optical module is generally 1310nm, 1550nm, which is used with single-mode fiber. Single-mode optical fiber has wide transmission band and large transmission capacity, which is suitable for long distance transmission.
The center wavelength of multimode optical module is generally 850nm, which is used with multimode fiber. Multimode fiber has mode dispersion defects, its transmission performance is worse than single-mode fiber, but the cost is low, suitable for smaller capacity, short-distance transmission.
Using long-range optical modules, the transmit optical power is generally greater than the overload optical power, so you need to pay attention to the fiber length to ensure that the actual received optical power is less than the overload optical power. If the fiber length is short, the use of long-range optical modules need to be used with fiber optical attenuation (fiber attenuation value per unit length in dB/km) to avoid burning the opposite end of the optical module.
Classification by central wavelength
The operating wavelength of an optical module is a range, and the parameter of central wavelength is used for the convenience of description, and the unit is nanometer (nm).
In order to support optical signal transmission using different optical wavelengths, optical modules with different central wavelengths are produced, such as: 850nm, 1310nm, 1550nm optical modules, etc.
Classification by color
The biggest difference between color optical modules and other types of optical modules is that the central wavelength is different.
The center wavelength of general optical modules are 850nm, 1310nm and 1550nm, the center wavelength is relatively single, we call this type of light "black and white light" or "gray light".
Color light module carries a number of different central wavelengths of light, so the intersection is colorful, we call this type of light for "color light".
Color light module is divided into two kinds of coarse set wave optical module (CWDM) and dense wave optical module (DWDM). In the same wavelength, there are more types of dense wavelength modules, so dense wavelength modules use the resources of the wavelength more fully. Light with different center wavelengths can be transmitted in the same fiber without interfering with each other, so the light from multiple color optical modules with different center wavelengths is combined into one way for transmission by passive combiner, and the remote end is divided into multiple ways according to different center wavelengths by splitter, which effectively saves fiber optic lines. Color optical modules are mainly used in long distance transmission lines.
Classification examples
According to the classification introduced above, the following are some examples of common optical module classifications.
Type | SFP-GE-LH40-SM1310 | SFP-10G-ER-1310 | QSFP-40G-LR4 | QSFP-100G-CWDM4 | QSFP-DD-400G-SR8 | |
|---|---|---|---|---|---|---|
Speed | GE | 10GE | 100GE | 400GE | ||
Package type | eSFP | SFP+ | QSFP28 | QSFP-DD | ||
Mode | Single-mode | Single-mode | Single-mode | Multimode | ||
Central wavelength（nm） | 1310 | 1310 | Black and white light | Black and white light | Color |
