Custom Mint Green 505nm 35mW Direct Diode Laser System - NT-LS-DM35-C

The NT-LS-DM35-C is a custom direct-diode laser system capable of outputting 35mW of 505nm laser light. It is built using a modified Coherent CUBE enclosure and a third-party diode mounting block and lens. The control electronics from Coherent have been removed and replaced by an ACS1500SE diode driver. The diode used is a Sharp GH05035A2G, operating at a wavelength of 505nm and up to 35mW 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. There is no temperature sensor or TEC in this laser system.

NT-LS-DM35-C laser system top view
NT-LS-DM35-C laser system front and back view

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. The driver in this unit has been configured to output 125mA to the laser diode, which is its normal operating current.

diode driver board and internal components

There is a small, cheap collimating lens installed in the threaded opening in the diode mounting block. This will eventually be replaced by a higher quality lens. The front of the unit has a manually operated shutter to block laser output when desired. The light output produced by this unit is acceptable for a custom laser assembled with mostly spare parts!

505nm laser beam

The beam resembles a pale green or "mint" color, but does show up differently on camera than in person. Comparing this 505nm laser to 488nm diode laser of similar output power, clearly shows the color difference. The 488nm appears more pale blue on camera. Both are excellent low-power wavelengths for experiments and projects!

505nm and 488nm laser beam comparison