1. Items and Definitions

1-2. Laser Diode Electrical and Optical Characteristics (1)

Item	Symbol	Definition	Remarks
Oscillation start current	Ith	The diagram below can be divided into two regions; a spontaneous emission region A and a laser oscillation region B. The oscillation start current is called "threshold current".
Operating current	Iop	Forward current required to maintain the specified optical power output.
Operating voltage	Vop	Forward voltage at the specified optical power output.
Wavelength	λp	It is the peak oscillation wavelength when the laser diode is operated at the specified optical power output. In the case of plural spectra, this is the wavelength of the center line of the set of spectral lines that have 1/2 of maximum intensity. The laser oscillation spectrum is classified into two kinds, that is, single longitudinal mode or multi mode according to the feature.