1. System principle:
When the power of 445nm or 532nm pure color laser is large enough, it can irradiate human body fluids (common carriers: fingerprints, sweat, blood, urine spots, fine spots, etc.), hair, dandruff, nails, bone fragments, fibers, footprints and other traces of evidence The fluorescent substance in the fluorescein can excite the inherent fluorescence reaction and emit fluorescence of different wavelength bands. After the blue or green light emitted by the laser itself is filtered through the filter, the inherent fluorescence of the trace evidence itself is revealed and can be directly photographed Extraction can effectively observe and record the signal light and images emitted by fingerprints and other traces. The blue laser is mainly aimed at searching for biological evidence such as forensic DNA. The green laser has a better display effect in the search and discovery of fingerprints and other traces. The 415 purple laser absorbs and darkens occult blood marks and blood fingerprints, and is used to search for murder scenes. There are certain effects and functions.

2. Performance and use:
The system solves the current difficult to realize the problems of diffuse reflection, fingerprints on penetrating objects, and DNA biological evidence discovery and collection. It can stimulate potential and obsolete traces that are difficult to find by ordinary means, and facilitate large-scale search and discovery on site, and prevent criminal evidence Omission.
1. It can directly stimulate human secretions (such as semen spots, vaginal secretions, saliva, sweat stains, etc.) at the crime scene to emit strong fluorescence;
2. It can directly stimulate the in vitro tissues such as nails, skin fragments and bone fragments to emit strong fluorescence;
3. It can directly stimulate finger prints on the surface of relatively smooth and semi-permeable objects such as the wall and paper surface of the crime scene
It emits fluorescence, and the fluorescence image of fingerprints can be extracted through the attached color filter;
4. It can directly find potential bruises under the skin of the human body, scars that have completely recovered on the body surface and traces of wall repairs;
5. It can directly find trace residues such as chemical fibers, explosion residues, and traces of some pesticides left on site.
6. Enhance the appearance of weak fingerprint traces treated with other fluorescent powder, 502, rhodamine, DFO and other conventional reagents.

3. Main features and advantages:
The core components of the series of high-power portable laser material evidence inspection system (also known as laser material evidence surveying instrument, searcher, discovery instrument, etc.) use imported high-efficiency lasers as light-emitting light sources, and adopt fully independent research and development of uniform light technology and heat dissipation system, and undertake the project of the Ministry of Public Security , High-end technology products independently researched and developed.
1. The design is simple and fashionable, and the workmanship is excellent. The whole piece of magnesium-aluminum alloy is precision-carved by CNC machine tools.
2. Superior performance: The uniformity of the light spot is far higher than that of similar imported products, which makes the physical evidence and the background object fluorescence have a better contrast effect.
3. Portability: The advanced and sophisticated heat dissipation device makes the dual-wavelength equipment of the system small in size and light in weight, as low as six kilograms, which is convenient for single police to carry to various crime scenes, reduces work intensity, and truly realizes portable survey sites .
4. Combined with the use of fluorescent occult blood display fluid, it has a very good display effect on occult blood marks and blood fingerprints on the surface of difficult objects such as leaves, textiles, leather, masonry, etc.
5. Combined with the use of natural pure plant-extracted fluorescent display powder, it can clearly display the sweat and grease fingerprint lines on the surface of difficult objects such as leather and plastic.
The system is small in size, light in weight, convenient to carry, simple to operate, uniform light spot, obvious fluorescence excitation effect, high discovery efficiency, high cost performance, etc. It is an extremely ideal crime scene investigation equipment for criminal investigation units at city and county levels.

4. Technical parameters:
1. Host technical parameters:
1) Violet laser wavelength: 415nm±2nm, basket laser wavelength: 445nm±2nm, green laser wavelength: 532nm±1nm, continuous non-pulse luminescence
2) The output power of the purple light terminal: 1W, the output power of the blue light terminal: 10W, the output power of the green light terminal: 6W, the power is adjustable;
3) Spot: Extremely uniform round spot, clear border without burrs, spot uniformity 98%;
4) Spot diameter: 40cm in diameter at 1 meter;
5) Dimensions: length, width and height are less than 250mm, 125mm, 135mm respectively
6) Weight: ≤6kg, including battery, convenient for single police to carry and use on site;
7) Output mode: optical fiber transmission, gun handle terminal output laser
8) Power supply mode: AC and DC;
9) Two portable carrying methods: shoulder-carried and hand-held
10) The service life of the laser light-emitting tube: more than 20,000 hours.
11) Battery management: More than 3 hours of battery life at full power, without reducing power as the battery power gradually decreases.
2. Technical requirements for light pipes
1) Optical fiber type: imported high flexibility and bending resistant quartz laser communication optical fiber;
2) Length: 1.2 meters as standard;
3) Installation method: fixed, not freely pluggable.
4) The optical fiber is covered with soft rubber tube, fiber layer, and retractable metal layer three-level protective armor.
3. Requirements for light emitting handle:
1) Gun-style handle design, when the operator holds the handle, it is difficult for the light outlet to aim at his face, which can effectively prevent
Light hurts human eyes;
2) The handle weighs 250 grams, which effectively avoids hand fatigue during long-term continuous work during on-site surveys.
3) The handle is equipped with laser switch key, power plus and minus and other control keys, which are convenient for operation and use during work;
4) There is a power and battery display on the handle, which can be viewed and controlled at any time during operation.
Quantity situation.
Fourth, equipment stability requirements
1) The equipment must not only be convenient to carry, but also meet the transportation requirements on bumpy roads. The whole machine must pass 90min/
0.1mm/50HZ vibration test;
2) The whole machine must pass the 30℃/70% constant temperature and pressure test;

5. Basic configuration:
1. One high-power blue-green laser host;
2. 1 battery charger;
3. Two sets of blue and green laser protective observation glasses;
4. 1 color filter for taking photos of physical evidence;
5. One set of occult blood fluorescence search reagent;
6. One bottle of green environmental protection fluorescent display powder;
7. One waterproof, dust-proof and moisture-proof safety protection box;