| Laser technology is widely used in military and civilian fields.According to different laser testing requirements,new requirements are also put forward for the measurement and testing of the main parameters of the laser.As a laser power test instrument,Laser Power Meter is widely used to measure the continuous laser power or the average power of pulsed laser.Fast and accurate laser power measurement is of great significance to scientific research and industrial development.Especially thermopile detectors made with thermocouples.It is a sensor that mainly detects and absorbs the rise of body temperature.It has nothing to do with the wavelength of the object to be measured.The measurement bandwidth can be very wide.It can be applied to the measurement of continuous radiation power and pulsed radiation energy of lasers in the ultraviolet to infrared band.Therefore,it is of great significance to carry out research on the design and fabrication of the thermopile laser power meter.This article mainly conducts in-depth research on the design and preparation of Thermopile Laser Power Meter.Based on the research theory of thermopile,the research is mainly carried out from the following two aspects:(1)The research on the chip structure design of MEMS Laser Power Meter was carried out.Through ANSYS simulation optimization,the paper compares the influence of key parameters such as the logarithm of the thermocouple bar,the length of the cold junction and the length of the thermocouple bar on the output response voltage.Finally,this paper determines the optimal structural parameters.The size of the thermopile chip completed in this paper is 1.8mm×1.8mm,and the thickness of the composite supporting film is 2.15μm.The research and development of MEMS thermopile chips is completed through the micro-nano manufacturing process,and the key preparation processes are studied.The thermopile chip test is completed by building an infrared test system.The test results show that the response voltage of the thermopile chip is 12.167mV and the response time is 26.9ms.Due to the parameters of the laser output including the wavelength of the laser beam,the pulse width and the size of the spot,the aging of the film in the absorption area of the thermopile chip is accelerated,the service life of the film is shortened,and irreversible local corrugated damage of the film occurs.Strengthen the research on the preparation of high damage threshold thin films for Laser Power Meter chips.(2)In the experiment,it is considered that the laser with high power and high energy will damage the thin film of the MEMS Laser Power Meter chip by strong laser light.Therefore,we have carried out exploratory research work on the structure design and key fabrication process of Laser Power Meter probe with high damage threshold absorption layer.Finally,the design scheme of package design and calibration circuit is proposed.This research provides reference value for the preparation of disc-type Laser Power Meter probe. |
