Custom Cyan 488nm 55mW Direct Diode Laser System - NT-LS-DC55-C

The NT-LS-DC55-C is a custom direct-diode laser system constructed using the casing and diode host of a Coherent CUBE laser head. The control electronics from Coherent have been removed. The laser diode is driven by an ACS1500SE mounted in place of the Coherent control electronics. The diode used is a Sharp GH04850B2G operating at a wavelength of 488nm and up to around ~55mW of output power. The driver board inputs have been connected to a DB-9 connector installed on the back of the unit in place of the original DE-15 connector. While there is a temperature sensor and TEC installed in this casing, it is not currently connected or in use in this particular laser system.

The NT-LS-DC55-C laser system

The ACS1500SE laser driver is capable of both boosting and bucking the power to deliver what is needed to the laser diode. It accepts an input range of 2.9-12VDC and can output up to 1500mA to the laser diode. This diode in particular has a nominal current of around 105mA and a maximum rated current of 135mA. The laser driver is set to output around 100mA to the diode, well under the rated current. This is done to preserve the life of the diode and keep the output power manageable. As currently configured, this laser outputs about 20mW but has not been measured using a precise instrument.

Diode driver board and internal components

The laser diode is mounted behind an adjustable lens. The front of the device has a manually operated shutter that can be closed to protect the glass lens when not in use or block laser output.

Diode host front view

The beam is cyan in color but does show up differently on camera than in person. This system is quite interesting as 488nm is a relatively uncommon laser wavelength. A Spectra Physics unit of similar power level and the same wavelength has sold used on eBay for over $1,000! The entire cost of this unit was around $120. It may not be quite as reliable as the Spectra Physics model, but for a custom laser, it's performance is exceptional.

Bright Cyan laser beam