Small laser diodes are compact semiconductor devices that emit coherent light, available in various wavelengths, power levels, and form factors for applications where space and precision are critical.

Overview

Small laser diodes are semiconductor devices that convert electrical current into a focused, coherent light beam. They are available in infrared, visible, and ultraviolet wavelengths, with output powers ranging from less than 1 mW to several watts depending on the application (DigiKey) . These devices are widely used in optical experiments, alignment systems, sensing, and compact electronics.

Compact Laser Diode Modules

Thorlabs LDM Series

• Wavelengths: 405 nm, 635 nm, 670 nm, 785 nm, 850 nm, 1550 nm
• Size: Ø1.40" × 5.8" housing
• Features: Fabry-Perot diode, collimating lens, built-in shutter, SM1 threads for mounting, power controller, remote interlock, key-lock switch, and adjustable output power
• Applications: Benchtop optical experiments, alignment aids, and integration with lens tube systems

ProPhotonix Compact Modules

• Size: 8–9 mm diameter, extremely small for space-constrained applications
• Power: Standard 0.9 mW or 4 mW, configurable on request
• Wavelengths: 520 nm, 635 nm, 650 nm, with custom options available
• Features: CW or TTL modulation, collimated or focused elliptical spot, line or cross optics, hard-anodized aluminum housing, battery-operable, high boresighting accuracy (<0.5°)
• Customization: Electronic, optical, and mechanical options for OEM applications

General Specifications

• Packages: TO-can (Ø5.6 mm, Ø9 mm), butterfly, laser pigtail, chip on submount
• Power Range: 0.2 mW to 2 W for standard diodes; specialized lasers like Quantum Cascade Lasers (QCLs) and Interband Cascade Lasers (ICLs) cover 3–11 µm wavelengths
• Mounting: Compatible with optical mounts, lens tubes, and V-groove mounts for precise alignment
• Applications: Alignment, sensing, barcode scanning, laser pointers, optical communication, and compact instrumentation

Considerations

• Power Supply: Many small laser diodes operate at low currents, allowing battery operation for portable devices
• Beam Characteristics: Collimated, focused, or line/cross outputs depending on the module
• Durability: Aluminum housings and anodized coatings improve mechanical stability and heat dissipation
• Customization: Many suppliers offer tailored solutions for wavelength, power, optics, and mounting to meet specific project requirements Small laser diodes provide a versatile, compact, and efficient light source for a wide range of applications, from laboratory experiments to embedded systems, with options for both standard and highly customized configurations.