Digital butterfly laser diode controller
Koheron CTL200 is the digital version of the popular CTL100 analog laser controller. It drives up to 200 / 400 / 600 mA laser current with a current noise density of only 230 / 450 / 670 pA/√Hz. The CTL200 fits in a 75 mm x 75 mm square, uses a single 5.9 V supply, and can operate between 0 and 50°C. The CTL200 is conduction-cooled. It comes with an aluminum base plate and a zero insertion force socket for easy mounting. The CTL200 is also available in a screw terminal version.
- CTL200 digital butterfly laser controller
- Base plate
- 5.9 V 3 A power supply
CTL200 laser controller is available for type 1 lasers (CTL200-1-) and type 2 lasers (CTL200-2).
B-200 (200 mA)
B-400 (400 mA)
B-600 (600 mA)
|Laser current||5 - 225 mA||10 - 450 mA||15 - 675 mA|
|Laser current resolution||5 µA||10 µA||15 µA|
|Compliance voltage at max. current||3.0 V||3.0 V||2.9 V|
|RMS noise (10 Hz - 1 MHz)||220 nArms||430 nArms||650 nArms|
|Current noise density (1 kHz)||230 pA/√Hz||450 pA/√Hz||670 pA/√Hz|
|1/f corner noise||100 Hz||100 Hz||100 Hz|
|Temperature coefficient||35 ppm/°C||35 ppm/°C||35 ppm/°C|
|Slow start (90 % setpoint)||5000 ms||5000 ms||5000 ms|
|Modulation gains||250 µA/V, 2.5 mA/V, 25 mA/V||500 µA/V, 5 mA/V, 50 mA/V||750 µA/V, 7.5 mA/V, 75 mA/V|
|3 dB modulation bandwidth||10 MHz||10 MHz||10 MHz|
|AC modulation cutoff frequency||80 kHz||80 kHz||80 kHz|
|Maximum current||1.15 A||1.15 A||1.15 A|
|Compliance voltage||±3 V||±3 V||±3 V|
|Temperature stability||0.002 °C/°C||0.002 °C/°C||0.002 °C/°C|
|Laser power monitor|
|Photodiode current||0 - 2.5 mA||0 - 2.5 mA||0 - 2.5 mA|
|Outside Dimensions||75 mm x 85 mm x 27 mm||75 mm x 85 mm x 27 mm||75 mm x 85 mm x 27 mm|
|Weight||104 g||104 g||104 g|
|Supply voltage||5.7 V to 6.5 V||5.7 V to 6.5 V||5.7 V to 6.5 V|
|Operating temperature||0 °C - 50 °C||0 °C - 50 °C||0 °C - 50 °C|
|Compatible lasers||Floating diodes / anode-grounded||Floating diodes / anode-grounded||Floating diodes / anode-grounded|
More Laser Drivers
Current stability is depicted in the following figure showing a 12-hour long evolution of current at 25 °C ambient temperature. A controller with 200 mA laser current (B-200) set at 200 mA was used for this measurement.
Current is stable within ±10 ppm.
The figure below shows the current variation of the controller for the 600 mA laser current version (B-600) operated at 550 mA for different ambient temperatures between 0 and 55 °C. The current is measured using a high precision 5 Ω resistor and a 7.5-digit digital voltmeter. Temperature coefficient is below 30 ppm/°C.
CTL200 controllers are calibrated at 21 °C by measuring the voltage across a high-precision 5 Ω resistor with a 7.5-digit digital voltmeter. Here is a typical result for the calibration for the 400 mA laser current version (B-400):
Relative residuals from a linear fit show that linearity is better than 0.1% for currents above 50 mA.
The CTL200 laser diode controller features a DC modulation which controls the current setpoint input with 10 MHz bandwidth. An AC input provides direct laser diode RF modulation for frequencies above 100 kHz.