Laser Diode Current Controller LQprO

Within our work on laser development we have developed a laser diode current controller. There are two versions:

an ultra-low noise current controller (up to 140 mA)
a low-noise current controller (up to 400 mA)

Feature List

LQprO-140

Noise characteristics of LQprO-140 compared to other systems

Parameters	Ultra-Low Noise	Low Noise	Units	Remarks
Output Current Range	0 – 140	0 – 400	mA	Other Currents on request
Output Current Resolution	22.4	64	µA
Output Current Accuracy	0.1	0.1	% FS
Laser Output Compliance Voltage	1.7 – 2.9	1.7 – 2.9	V	Other Voltages on request
Temperature Coefficient	< 25	< 85	ppm FS/°C
Output Current Short-Term Stability	< 0.9	< 0.9	ppm FS	10 minutes
Output Current Long-Term Stability	< 3.3	< 3.3	ppm FS	1 hour
Output Current RMS Noise	< 21	< 60	nA	10 kHz – 100 kHz
	< 92	< 265	nA	10 kHz – 1 MHz
Output Current Noise density	< 300	< 850	pA/sqrt(Hz)	10 kHz – 1 MHz
Current Limit Range	0 – FS	0 – FS	mA
Current Limit Resolution	70	200	µA
Current Limit Accuracy	0.1	0.1	% FS
Display Resolution	0.1	1	mA
External Analog Modulation Input Impedance	1k	1k	Ohm	Slow Mod
	50	50	Ohm	Fast Mod
External Analog Modulation Input Range	-10 – 10	-10 – 10	V	Slow Mod
	-10 – 10	-10 – 10	V	Fast Mod
External Analog Modulation Transfer Function	8 – FS	12 – FS	mA/V	Slow Mod (Adjustable)
	1	1	mA/V	Fast Mod
External Analog Modulation Bandwidth (3 dB)	200	200	kHz	Slow Mod depending on Laser Diode
	up to 150	up to 150	MHz	Fast Mod depending on Laser Diode
Display Type	LCD Backlit	LCD Backlit