The optical transceiver NTC thermistor chip produced by EXSENSE Electronics Technology Co., Ltd. adopts advanced semiconductor manufacturing process, combined with self-developed NTC thermistor materials and processing technology, to ensure its continuous production of high stability, high reliability. The NTC thermistor chip of optical transceiver sold by EXSENSE Electronics plays a role of temperature monitoring and temperature control in the optical module, which can effectively ensure its normal operation.
Optical transceiver, as one of the cores of medium-long distance optical communication, plays the role in photoelectric conversion. Today, EXSENSE Electronics will introduce the main components in the optical transceiver - TOSA and ROSA.
TOSA
TOSA is the main component of optical transmitter module. It mainly converts electrical signals into optical signals. The TOSA can be classified into SC TOSA, LC TOSA, FC TOSA, and ST TOSA by adapter type. TOSA includes components such as optical isolator, monitoring photodiode, LD drive circuit, NTC thermistor chip, thermoelectric cooler, automatic temperature control circuit (ATC) and automatic power control circuit (APT).
Among them, the optical source (semiconductor emitting diode or laser diode) is the core, the LD chip, the monitoring photodiode and other components are encapsulated in a compact structure (TO encapsulation or butterfly encapsulation) and then make up the TOSA.
In TOSA, LD laser diode is currently the most commonly used semiconductor emitting device for optical transceiver. It has two main parameters, threshold current (Ith) and slope efficiency (S). In order for the LD to work quickly, must provide the LD with a DC bias current IBIAS which is slightly above the threshold current, that is, the laser is only emitted when the forward current exceeds the threshold current.
ROSA
ROSA is an optical receiving assembly. In a high data rate optical transceiver, a PIN or ADP photodiode and TIA are usually assembled in a sealed metal housing to form the ROSA optical receiving assembly.
The main component of ROSA is photodetector, which is used to convert optical signals into electronic signals through photoelectric effect. Common photodetectors in optical communication are PIN photodiode and avalanche photodiode (APD). APD is a highly sensitive photodetector which uses avalanche multiplier effect to double the photocurrent. Compared with PIN photodiode, the sensitivity of APD receiver can be improved by 6 to10dB.
