The Coherent Sapphire 561-50 is a 561nm OPSL laser system capable of a maximum output power of 50 mW. This laser system was purchased online and came attached to a heatsink and fan assembly along with a shielded flexible fiber and KineFlex coupler/adjustable mount. The fiber is 15-feet long, which is quite surprising. At that point why not consider relocating the laser source closer to the target. It also came with the matching OEM controller LP USB. This laser system likely was pulled from a piece of equipment manufactured by BD Biosciences, based on some component labels and part numbers. Please note that this is a supplementary writeup for this particular laser system. For much greater detail regarding Sapphire OPSL laser systems including theory of operation, technical info, and the beam path diagram, please refer to the master writeup for the Sapphire 548-300 laser system linked below.
This system originally came with a very fancy shielded fiber with KineFlex adjustable mount and quick disconnect. The designers of this assembly really went the extra mile with that little clamp on the front supporting the shielded fiber. The baseplate and heatsink are precision machined aluminum and are of excellent quality. The small module in front of the laser output window is just a machined aluminum block with a hole for laser light to pass through to the KineFlex mount secured to the front. This was needed because most Coherent Sapphire models do not have a built-in method for attaching a fiber. However, there are Sapphire models where the laser light terminates into a non-removable fiber.
We decided to remove the KineFlex mount and fiber as it was not needed and significantly degraded the beam intensity. We also removed the fiber clamp and solid aluminum arm that was mounted to the front of the baseplate.
Here is a top view of the system. You can clearly see how the adapter block is mounted right in front of the Sapphire's output aperture, but it does not actually touch the laser head casing. We decided to leave the adapter block in place as it does not interfere with or degrade the beam at all and will be useful if we ever want to re-install the fiber delivery system.
The side profile shows the laser head information label, heatsink assembly part numbers, and what looks like a test ID QR code. This is probably just from the eBay seller and not an actual calibration tag. The baseplate is secured to the frame of whatever device it came from by two captive screws in the front, and a cutout for a pin in the back. This makes the whole laser assembly easy to remove and swap out if needed.
On the back of the heatsink is a large, but quiet cooling fan. It moves sufficient air and is barely noticeable when run at 12V DC. On the back of the laser head is the DB-25 interface connection for the OEM controller, a two-pin external fan connector, and an emission indicator.
This is the Sapphire OEM controller LP (USB version). There are several variants of controllers for the Sapphire lasers. Generally they will be LP or HP for low power/high power respectively, or LPX models for more exotic Sapphire lasers. The USB version has both a USB Mini-B connector and a DB-9 connector. They are both RS-232 serial interfaces and serve exactly the same purpose. The USB plug is just connected to an FTDI USB-to-serial converter on the board. Lastly, there is an analog variant of the Sapphire OEM controller that only has a DB-9 serial port but also includes an additional DB-25 connector purely for a bunch of analog I/O. The analog version is two stacked boards that are twice as long as the USB version. To make the lineup even more confusing, the OEM controller USB version does have an analog interface connector in the form of a 26 pin IDC connector on the board, however the LPX controllers seem to omit this entirely and have no analog interface at all. Why didn't they just make an all-in-one controller? It would have been much simpler.
Below is a picture of the back of the controller. The MCU running the show is an MC908GP32 (M68HC08) 8-bit microcontroller with a wide variety of features including built-in flash.
The beam produced by this laser is not quite as vibrant as typical 532 nm green. It's much more pale and almost resembles yellow in person. On camera, it just looks like a typical green laser wavelength.
The beam quality is exceptional, nearly as good as a gas laser. It outperforms most other direct-diode and diode-pumped laser systems.
We placed the Sapphire 561 (right) next to the Sapphire 548 (left) on the bench to compare the beams. In person, the difference is subtle but certainly noticeable. On camera (and in pictures) they are nearly indistinguishable. However, there is some excellent speckle visible on the wall behind the lasers.
