A diode laser's tracking ratio is a comparison of milliamperes of current in use to milliwatts of light generated. A monitor photodiode tracks the light leaving the back of the laser cavity to gauge the millwatts. This ratio is used to check for any flaws in the fiber mounting; flaws will cause this ratio to fluctuate. The L/I curve determines a laser's drive current at any desired level of optical power as well as the level of current where the laser becomes active. This curve indicates how efficient a diode laser is working, in milliwatts per milliampere. The V/I (sometimes called I/V) curve measures changes in forward voltage as the current increases.
Diode lasers do not shoot out in one unified beam. Instead, they shoot out in a conical pattern, which is slightly asymmetric because the beam comes out of a slit instead of a hole. The far-field pattern will show you the width of the base of the cone as it changes with increased current. A near-field pattern takes it images near the source of the laser and measures the intensity of each individual element within the beam.
Tunability measures a laser's susceptibility to wavelength change in response to changes in current and temperature. Spectral width refers to the distance across a given beam's spectrum. While this is more difficult to see with the naked eye than it is for white light beamed through a prism, each laser beam is not a unified ray of one color or element but has its own spectrum. Laser diode spectra generally measure two to three nanometers.
As of March 2011, dynamic characteristics of diode lasers are a field of exploration. Generally, these come into play when researchers or manufacturers want to simulate circuits in real-time situations when working with beta versions of diode lasers, or when modulating existing models.
As with any light source, the output is capped by the surfaces that reflect and refract the light before it leaves the device. Most laser diodes have optical resonators which will multiply the intensity at what is called the optical threshold, giving the beam considerably more intensity than that from other diodes.