SINGLE WAVELENGTH SEMICONDUCTOR LASER HAVING PLURAL INTEGRATED MONITOR PHOTODETECTOR WHICH HAS DIFFERENT ABSORPTION WAVELENGTH BAND

摘要

PURPOSE: A single wavelength semiconductor laser having plural integrated monitor photodetector which has different absorption wavelength band is provided to be used as the photoelectric source of a WDMA system. CONSTITUTION: In the method of manufacturing a single wavelength semiconductor laser, a diffraction grating layer(3) is formed on an n-InP substrate(2) through holographic or exposure method. In turn, layers of multiple quantum well activation layer(4), a photoelectric Ga layer(5), a p-InP clad layer(6) and a p-InGaAs layer(7) are formed. And a monitor PIN photoelectric detector is formed after etching. An InGaAsP/InGaAs layer(12) is formed on the exposed part of the n-InP substrate(2) and a p-InGaAsP layer(17) is formed making a first photoelectric detector along with the InGaAsP/InGaAs layer(18). Then a second photoelectric detector is formed with a semi-insulating InP layer(15), an n-InGaAs layer(14), an InGaAsP/InGaAs layer(12), a p-InP clad layer(11) and a p-InGaAs layer(10). A separating layer(9) is formed by inserting semi-insulating InP in to a trench formed by etching separating area for layer and photoelectric detection. Finally, a pair of electrodes are connected to the device.