Laser Diode Size and Specifications

Laser diode chips are typically very small, often around 1 mm × 0.5 mm, while packaged diodes commonly come in standard TO-can sizes of 5.6 mm or 9 mm in diameter.

Laser Diode Chip Dimensions

The active semiconductor region of a laser diode, where lasing occurs, is extremely small. Most edge-emitting laser diode chips measure approximately 1 mm in length and 0.5 mm in width, with the active layer being only a few micrometers thick . Surface-emitting laser diodes (VCSELs) can be even smaller, often just a few hundred micrometers across, due to their vertical emission design .

Packaged Laser Diodes

For practical use, laser diodes are usually mounted in protective packages. The most common packages are TO-can types, with diameters of 5.6 mm or 9 mm, which house the chip, electrical connections, and sometimes a photodiode for power monitoring . Other package types include butterfly packages, laser pigtails, and chip-on-submount configurations, which vary in size depending on cooling requirements and optical coupling .

Beam and Emission Considerations

The small size of the laser diode chip results in a highly divergent beam, often elliptical in shape. The beam diameter at the exit face is typically on the order of a few micrometers to tens of micrometers, depending on the design and wavelength . Optical elements or fiber coupling are often used to shape or guide the beam for applications.

Summary

• Chip size: ~1 mm × 0.5 mm (active region only)
• Active layer thickness: a few micrometers
• Standard TO-can packages: Ø5.6 mm or Ø9 mm
• Other packages: butterfly, pigtail, chip-on-submount
• Beam diameter at exit: a few micrometers to tens of micrometers These dimensions make laser diodes compact and suitable for integration into a wide range of optical and electronic systems, from fiber-optic communications to consumer electronics .