Optoelectronics Infrared Glossary of Terms

Term	Definition
Aperture Width	Width of the built-in openings in front of the emitter and photosensor that define the size of the beam.
BV_CEO>	Collector-Emitter Breakdown Voltage with the base open.
Emission Angle @ 1/2 Power	Angle of the cone where the light intensity is half that on the optical axis.
I_CC Supply Current	Current drawn from the supply at a given voltage.
I_CEO	Collector-Emitter current for radiant sensitive devices when the base is open and without radiant incidence.
I_F	Current flowing through a diode from anode to cathode.
I_F+	Diode forward current (I_F) required to cause the output to turn on.
I_F-	Diode forward current (I_F) required to cause the output to turn off.
I_R	Current flowing through a diode from cathode to anode.
I_R(D)	Reverse dark current for a given supply voltage.
Lead Spacing	Distance between the leads from the emitter side of the package to the photosensor side.
Light Current	Current which flows through a device due to radiant incidence.
Negative Threshold	Amount of incident light at which the device turns off.
On-State Collector Current	Collector current at a specified radiant incidence and a specified collector voltage.
Operating Supply Voltage	Voltage under which the device operates.
Output Configuration	Output circuit and function.
Output Power	The radiant intensity of emitted light measured in mW/sr.
Positive Threshold	Amount of incident light required to turn the device on.
Reception Angle @ 1/2 Power	Angle of the cone where the sensitivity is half that on the optical axis.
V_F	Voltage between anode and cathode at a specified forward current.
V_R	Voltage between cathode and anode at a specified reverse current.