Optical properties:
Color perception: both of 505nm and 532nm green laser diode modules are belonging to green light, however, 505nm light is more yellow-green, while 532nm light is a more standard and pure green. Under operation with the same output power, human eyes are relatively more sensitive to 532nm green light, thus it gets even more visible and brighter laser light source in distance and high lighting occasion as well. When laser light is propagating in the atmosphere, according to the Rayleigh scattering principle, the shorter the wavelength, the more obvious the scattering, so the scattering of 505nm green laser in the atmosphere will be relatively stronger than than of 532nm.

Technical principle and manufacturing differences: 
Generation method: 532nm green laser diode module is usually generated by frequency doubling 1064nm infrared lasers through nonlinear optical crystals. 505nm green laser modules are generally generated by some special semiconductor materials or specific laser gain media under the excitation of a suitable pump source. Usually direct laser diode made laser device gets even more stable and longer time lasting dot alignment performance in continuous use. Owing to quite mature manufacturing processing of 532nm green DPSS laser tech, while 505nm green laser may be relatively difficult to manufacture, getting special requirements for materials and processes, thus 532nm laser gets low price than 505nm green laser.

Applications fields:

In the field of beauty, green laser light emitted via a 505nm green laser diode module can inhibit the proliferation of melanocytes and the activity of tyrosinase, which is helpful for whitening and freckle removal. In some of scientific research experiments, such as specific biological cell imaging, photochemical experiments, etc., 505nm green lasers may also be applied because of their specific optical properties.

532nm green laser diode module gets special use for industrial processing, such as glass making, film etching, which can achieve fine pattern engraving and precise cutting. It can also be used for indicating measurement, such as marking line positioning in construction, alignment of equipment installation etc, entertainment fields, such as stage lighting effects and laser performance etc.

Applications Difference Analysis:

Industrial field

505nm laser diode module can be used in laser power tools, using its specific wavelength characteristics to achieve some special material processing or specific process requirements, such as micro-processing of some special plastics that absorb 505nm wavelength well. 
532nm laser diode module is commonly used in industrial cutting, welding, marking, etc., such as high-precision cutting of thin metal sheets. Due to its high energy density and good focusing performance, it can achieve fine pattern engraving and precise material cutting.

Medical beauty field

In medical beauty field, 505nm green laser can be used for whitening and freckle removal, and improve skin pigmentation problems by inhibiting melanocyte proliferation and other effects. In medical treatment, it can be used for some specific phototherapy, such as auxiliary treatment for certain skin inflammations. 532nm green laser is mainly used for dermatology, such as treatment of superficial pigmented lesions such as freckles, coffee spots, and age spots. The 532nm wavelength in the ultra-picosecond device can be used to treat shallow spots.

Measurement and positioning field

505nm laser is used in infrared temperature measurement, laser rangefinder, laser level and other equipment to provide a baseline or reference point for measurement. A 532nm laser module is used in scenes, such as construction and equipment installation, which is often used as a tool for marking and alignment, such as floor marking and vertical positioning of walls in large-scale construction.

Scientific research and education field

505nm laser module is applied for some biological cell imaging experiments, the 505nm wavelength may be more conducive to observing certain specific cell structures or biological molecular fluorescence characteristics. 532nm laser module is often used in scientific research such as spectral analysis and optical experiments. Due to its high monochromaticity and stability, it can provide high-quality light sources for experiments.

Indication and entertainment field

505nm green laser diode module can be applied to laser barcode scanners, using its unique wavelength characteristics for barcode scanning and recognition. 532nm laser is often used in stage lighting effects and laser performances, which can produce bright and eye-catching green beams, creating colorful visual effects. It is also commonly used as a laser pointer to provide instructions in teaching, meetings and other scenarios.