A wide spectrum infrared laser source can be designed by using a super luminescent light emitting diode (SLED) and an erbium doped fiber amplifier. This laser source can be used for detecting the atmosphere CO2 concentration with high precision, and this detecting technology is based on the ultra fine atmospheric CO2 absorption spectrum. The spectrum of SLED is much wider than that of the differential absorption lidar, and it has no use for high frequency locking technology. Also, this technology can avoid differential absorption lidar measurement error by on wavelength shift. The experimental results show that the laser center wavelength is 1584 nm, spectral range is from 1564 nm to 1604 nm, output power is 2 W, and the max gain of the fiber amplifier is 34 dB at this spectral range. This laser has advantages of small size, high power, low cost and easy to carry, and it can help for the development of atmosphere CO2 concentration detecting by the wide spectrum infrared lidar technology.