878.6nm 90 W Wavelength-Stabilized Fiber Coupled Diode Laser

The M878.6±0.5-90-D200/22-C5-P is a high‑power, fiber‑coupled laser diode module from PhotonTec Berlin designed for OEM and industrial integration. It delivers 90 W of optical output power at a central wavelength of 878.6 nm (tolerance ±0.5 nm), with a very narrow spectral width of 0.5 nm (FWHM). The module is fiber‑coupled into a 200 µm core diameter multimode fiber with 0.22 numerical aperture (NA) and an SMA905 connector. Typical electrical parameters include a threshold current of 1.4 A, operating current up to 12.5 A, operating voltage of about 16 V, slope efficiency of 9 W/A, and power conversion efficiency around 48–50%. The specified operating baseplate temperature is 20–30 °C, with storage temperature from –20 to +80 °C and operating humidity below 75%.

A 90 W, 878 nm fiber‑coupled laser such as the M878.6±0.5-90-D200/22-C5-P is typically used in applications requiring high optical power and efficient coupling into multimode fiber. Common uses include: 1) Diode pumping of solid‑state lasers (especially Nd:YVO4 and Nd:YAG) where 878–880 nm pumping improves efficiency compared to 808 nm. 2) Materials processing and micromachining (plastics welding, soldering assistance, thin metal pre‑heating) using direct diode output. 3) Medical and aesthetic platforms (e.g., as a pump source in DPSSL‑based systems) when integrated into certified equipment. 4) Illumination and research applications in spectroscopy or fluorescence excitation where narrow‑band, high‑power near‑IR light is needed. The 200 µm, 0.22 NA SMA905 fiber output is standard in many OEM and lab setups, simplifying integration with existing optics and delivery fibers.

The emission wavelength of the M878.6±0.5-90-D200/22-C5-P shifts with both temperature and drive current, which is typical for high‑power diode lasers. The wavelength temperature coefficient is specified as 0.02 nm/°C, meaning the central wavelength increases by about 0.02 nm for every 1 °C increase in the baseplate temperature. The wavelength current coefficient is 0.05 nm/A, so the wavelength increases by about 0.05 nm for each additional ampere of drive current. Within the specified baseplate temperature range of 20–30 °C and the operating current range up to 12.5 A, you can estimate and manage the wavelength by controlling both heat sinking and current. For applications that require accurate wavelength locking around 878.6 nm (such as efficient pumping of Nd‑based crystals), a temperature‑controlled mount or TEC‑stabilized baseplate is recommended to keep the wavelength within the desired tolerance.

For reliable and long‑lifetime operation, the M878.6±0.5-90-D200/22-C5-P must be mounted on an adequately sized heat sink or temperature‑controlled baseplate. The specified operating temperature of 20–30 °C refers to the baseplate of the diode case, not the ambient air. Because the module can output 90 W of optical power with roughly 50% electrical‑to‑optical efficiency, a comparable amount of heat (on the order of 90 W) must be removed continuously. In practice, most OEM users mount the module to a water‑cooled or TEC‑stabilized cold plate with good thermal interface material and monitor the thermistor embedded in the package for feedback. Operating the device outside the recommended baseplate temperature range can lead to wavelength drift, performance degradation, and reduced diode lifetime, so thermal design is critical in the host system.

The module should be driven by a low‑noise, current‑regulated laser diode driver with programmable current limits and slow‑start/soft‑start capability. The threshold current is about 1.4 A, and the typical operating current is up to 12.5 A at around 16 V, so the driver must support high currents while maintaining stability. To protect the laser diode, use: 1) Proper ESD protection and handling, since the diode is sensitive to static discharge. 2) Reverse‑polarity protection and interlocks to prevent accidental overcurrent. 3) Monitoring of the integrated photodiode, if used, to implement power feedback control. The pinout includes laser diode anode and cathode, photodiode anode and cathode, and thermistor connections. Following PhotonTec Berlin’s recommended wiring and using a driver rated specifically for high‑power fiber‑coupled diodes will maximize safety and device lifetime.

The M878.6±0.5-90-D200/22-C5-P is explicitly classified as an industrial OEM laser diode module and is intended only for integration into other equipment. According to the datasheet, this product itself does not comply with IEC and CDRH laser safety requirements. The responsibility for obtaining IEC 60825‑1 and CDRH (FDA) certification lies with the system integrator who incorporates this laser into a complete product. It is therefore not suitable as a consumer stand‑alone laser source. When integrating it into a system, you must add appropriate housing, safety interlocks, emission indicators, key switches, and labeling to meet the relevant laser safety standards and local regulatory requirements.

This 878 nm module uses a 200 µm core multimode fiber with 0.22 numerical aperture and an SMA905 connector. This configuration is widely used for high‑power diode lasers and is compatible with standard SMA905 fiber collimators, couplers, and delivery cables. Compared to similar products listed on FindLight and from other laser diode vendors, 200 µm/0.22 NA with SMA905 is a typical choice for 50–150 W class diode modules because it provides a good balance between high coupling efficiency and manageable beam quality. Many comparable 808–980 nm fiber‑coupled pump diodes offer similar fiber parameters, but may differ in center wavelength, power level, and package type. If your system already uses SMA905 multimode fibers, this module can generally be integrated with minimal changes to the optical delivery path.