QSI TO18-5.6mm Packaged 635nm 20mW Red Laser Diode
The QL63H5SA/B/C-RI is a high-performance 635nm red continuous wave (CW) laser diode, engineered to deliver a reliable 20mW optical output—making it an ideal light source for optical level applications. It operates as a single transverse/TM mode laser, ensuring stable, consistent emission for precision use cases.
This diode combines robust performance and practical design:
- Core Specifications (at 25°C case temperature): It runs on a typical 2.3V operating voltage (max 2.6V) and 65mA operating current (max 85mA) at 20mW output, with a low 40mA typical threshold current (max 60mA). Its slope efficiency hits 0.7mW/mA (range: 0.4–1.0mW/mA) for efficient energy conversion.
- Optical Performance: The 635nm lasing wavelength (range: 634–644nm) produces bright red visible light, paired with controlled beam divergence (typical 9° parallel, 30° perpendicular) and tight beam angle tolerance (±3°) for focused, accurate propagation.
- Durability & Integration: Housed in a compact 5.6mm package, it includes a built-in photo diode (30V reverse voltage rating) for performance monitoring. It operates reliably in -10–50°C temperatures (storage range: -40–85°C) and requires APC (Auto Power Control) operation with a heat sink (do not exceed 20mW at 50°C).
With its balanced power, stable mode operation, and compact form factor, this laser diode suits industrial and professional devices needing precise, low-power red laser output.
Core Specification:
| Wavelength | 635nm |
| Output Power | 20mW |
| Working Voltage | 2.3V |
| Package | TO18 5.6mm |
| Condition | Original package and brand new |
| Lifespan | > 10,000 hours |

BU-LASER has other Laser diodes from 375nm to 1064nm:
| Color | Wavelength | Power Range | Package |
| UV | 375nm | 500mW | TO5-9mm |
| UV | 380nm | 200mW | TO18-5.6mm |
| Violet | 395nm | 300mW | TO18-5.6mm |
| Violet | 405nm | 20mW-3W | TO18-5.6mm /TO5-9mm |
| Blue | 425nm | 1.5W | TO18-5.6mm |
| Blue | 435nm | 5W-7W | TO5-9mm |
| Blue | 450nm/455nm | 80mW -5.5W | TO18-5.6mm /TO5-9mm |
| Blue | 462nm/ 465nm | 1.4W- 2.8W | TO5-9mm |
| Cyan | 488nm | 55mW-300mW | TO18-5.6mm |
| Green | 515nm/520nm | 10mW-1.6W | TO18-3.8mm/TO18-5.6mm/TO5-9mm /Frame |
| Red | 635nm/638nm/642nm | 5mW-2.5W | TO18-3.8mm/TO18-5.6mm/TO5-9mm |
| Red | 650nm /658nm/660nm | 5mW-1W | TO18-3.3mm/TO18-3.8mm/TO18-5.6mm/C-mounted / Frame |
| Red | 670nm | 5mW | TO18-5.6mm |
| Infrared | 780nm/785nm | 5mW-200mW | TO18-5.6mm |
| Infrared | 808nm | 200mW-5W | TO18-5.6mm/TO5-9mm/C-mounted |
| Infrared | 830nm | 30mW-300mW | TO18-5.6mm |
| Infrared | 850nm | 5mW-2W | TO18-5.6mm |
| Infrared | 905nm | 15W-75W | TO18-5.6mm |
| Infrared | 940nm | 250mW | TO18-5.6mm |
| Infrared | 980nm | 50mW-1W | TO18-5.6mm/TO5-9mm |
| Infrared | 1064nm | 50mW | TO18-5.6mm |










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