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The core applications of 5G are the Internet of Things, Internet of Vehicles, big data collection and other application fields. Among them, mobile phone 3D cameras, lidar, driverless sensors and other devices often work under the working conditions of narrow pulse and high current in practical applications. For example, the core device of a mobile phone 3D camera is a VCSEL semiconductor laser array, and in a small area, there are often tens to hundreds of laser IC arrays. In practical applications, it is necessary to provide an ultra-narrow pulse current to the laser to drive the laser to emit an ultra-narrow pulse laser. Well, it needs to reach μs or even ns level. This laser array IC, as well as the testing of subsequent serial packaging, must have an ultra-narrow pulse current source up to 30A.

The testing of laser chips is relatively complicated, involving optical and electrical measurements, and the difference in packaging forms must also be considered. The measurement of laser chips generally depends on LIV (light intensity-current-voltage) data. The photoelectric parameters are greatly affected by heat. As the temperature rises, it will directly affect the laser output power, threshold current density, electro-optic conversion efficiency, differential Quantum efficiency, degree of polarization and other properties will lead to a decrease in the life and reliability of semiconductor lasers, and even damage to the chip, which will eventually affect the reliability of the device. In addition, the test results of high-power laser chips under DC and wide pulse conditions are inaccurate; fluctuations in power supply will affect the life of the laser, and at the same time cause optical power instability and device heating instability.

Typical solution of laser LIV narrow pulse test system

The research and development of optical device testing equipment involves cutting-edge small signal processing technology, radio frequency circuit technology, high-speed circuit technology, digital signal processing technology, embedded software development technology, automatic control technology, engineering technology, etc., and is highly comprehensive , requires companies to have a long period of technical and theoretical accumulation in their own fields, and the barriers to entry are high.

In order to meet the needs of the laser industry chain for narrow-pulse LIV testing, Proces Instruments has conducted in-depth discussions with leading companies in multiple application fields. Based on years of technical precipitation and innovation, it has launched a PL narrow-pulse LIV testing system.

PL series narrow pulse LIV test system consists of PL series pulse constant current source, test fixture, integrating sphere, optical fiber, spectrometer, etc. 

Test principle 

LIV test uses pulse current power supply to the laser, and measures the voltage at both ends of the device and the output optical power of the device. As a precise current pulse source, the LIV test system drives the laser to emit laser light with different wavelengths. The laser light is collected by a special integrating sphere. The integrating sphere attenuates the energy of the light with a certain divergence angle, and then uses PD for photoelectric conversion. The system The photocurrent is sampled quickly, so as to accurately measure the laser power output by the laser. The classic test principle combined with the excellent performance and strict index requirements of the Proceeds PL test system has helped industry users complete a series of challenging test projects.

System advantages

Integrating multi-meter functions into one, realizing one machine with multiple functions:

Fast pulse generator + programmable current source + peak sampling optical power meter + pulse voltmeter

• Through the digital function of 15MS/s, the basic measurement accuracy of 0.1% of the pulse generator is realized;

• Ultra-narrow to ns-level pulse, the duty cycle can be as low as 0.01%;

• Multiple precision photocurrent test ranges;

• Upper computer LIV algorithm, supports automatic calculation of various parameters

Pulse high fidelity: pulse without overshoot, no oscillation

• The fastest pulse rise time 300A/μs

• Maximum 30A pulse current output;

• Compatible with CW and QCW modes, precise pulse width adjustable technology;

• Ultra-high-speed pulse sampling technology to ensure accurate sampling data under narrow pulses

Larger test current, more possibilities

• Can connect up to 4 sets of Pusyce PL series equipment in parallel;

• Provide a maximum driving current of 120A and μs pulse width;

• Realize LIV test of high-power laser on the same host computer software

Host computer test software is rich and powerful

• The system is equipped with special host computer software;

• Realize rapid testing and improve testing efficiency.

       In the measurement of optical parameters such as laser spectral characteristics, the testing machine still needs a current source to power the device. According to the actual application, there are two modes: CW and QCW. It is recommended to use the precise PL series narrow pulse test system for integrated use. As a constant current source, the PL series can also provide I/O interfaces and reasonably designed test fixtures for spectrometers, other automation equipment, and expansion interfaces at the same time, so as to realize the automatic testing of all parameters of the testing machine.

Typical Application

Precise Instruments uses advanced test and measurement technology as the cornerstone of the research and testing needs of the semiconductor industry, and keeps pace with the times to provide professional and reliable test and measurement equipment for laser testing and aging application scenarios. Breaking through traditional testing solutions will help you achieve more efficiently test target.

PL series laser LIV narrow pulse test system, HCPL series high-power laser test power supply, LDBI series multi-channel high-power laser aging system, etc. For more product and program details, please contact us for consultation.