Quantum X align

With the fiber illumination unit, the fiber core can be easily located using the Quantum X align touchscreen. First, the print field on the fiber array is defined by manual coarse alignment with a double-tap on the touchscreen. Then, Quantum X align automatically detects the position of the fibers with submicron accuracy and compensates for smallest substrate tilts during the print in all spatial directions.

For this, the autofocus routine first detects the surface of the optical fiber. Next, the system identifies the illuminated fiber core and marks the center of the core as the origin of a virtual coordinate system to which the print object is aligned. The virtual z-axis and its orientation in space is determined by moving the substrate downwards and identifying the position of the fiber core on multiple positions along this vertical movement of the stage. As a result, the optical axis orientation is detected and set as the virtual z-axis for a tilt compensated printing of microoptics with submicron precision.

To support the fiber printing workflow, Quantum X align is equipped with a red LED fiber illumination unit. Up to 32 individual fibers with standard PC or APC connectors can be plugged into this unit. The specially designed fiber substrate holder secures single fibers or fiber arrays and can load up to four fiber arrays at a time. Once inserted into the printer, the illuminated fiber cores can be easily identified using the live microscope view on the 18.5-inch touchscreen of Quantum X align. A double tab on the screen allows the stage to be moved to any position within the 50 x 50 mm² print area. A crosshair can be activated to facilitate the rough alignment on the screen, and intuitive gestures let you zoom in and out on the screen.

The new workflow can load multiple .stl or .obj files and merge them to one single print object. This enables the user to set individual print parameters, such as slicing, hatching, laser power or scan speed, for each individual part of the print object. As a result, support structures can be printed faster with coarse parameters, whereas optical parts such as the surface of a lens can be printed with finer settings that result in a surface roughness (Ra) of 10 nm and even less. Of course, predefined print parameters are available out of the box but can also be customized to fit the design and specific requirements. The individual parts are then merged to one print project and uploaded to Quantum X align.

Adjusting print parameters to the functional requirements of the print object saves valuable process time and enables Quantum X align to process an 8x V-groove fiber array in less than 20 minutes.

Quantum X align features a high precision confocal imaging module for 3D mapping of substrate topographies. This module is integrated into the beam path of the near-infrared printing laser. The laser beam is scanned over the sample surface and the back-scattered light is confocally detected by the system. High resolution 3D topographies are recorded by moving the stage vertically and repeating surface scans multiple times along the z-axis. A spatial filter pinhole in front of the detector ensures that only light from the focal plane is detected, resulting in a lateral detection accuracy down to 100 nm. Thus, the confocal module measures real 3D topographies and is more precise than image-based measurements using the system camera.

The 3D alignment of the print object is based on the high-resolution 3D topography mappings by the confocal unit. For the precise alignment of optical components on a photonic chip, smart software algorithms automatically identify predefined markers and topography features. Thus, the exact position and orientation of the waveguides on the chip can be determined. A virtual coordinate system is then set to the exit of the waveguide, perfectly aligned with its optical axis and orientation. The desired optical components are printed with respect to this coordinate system, ensuring best optical performance and minimizing coupling losses. This enables efficient light coupling by Free Space Microoptical Coupling (FSMOC).

Printing onto a chip’s facet from top, i.e. perpendicular to the substrate surface, is a challenging task and requires not only a precise positioning system but also smart solutions to overcome the “shadowing effect”: When printing onto a facet, a substantial part of the intensity in the focal point of the printing laser is lost, because the light is partly blocked by the edge of the substrate. Close to the substrate wall the shadowing effect is more prominent and requires higher exposure doses. Quantum X align automatically compensates for this effect using a patent-protected process and dynamically adjusts the exposure conditions during printing. This results in microoptics and other print objects written onto the facet of a substrate with submicron shape accuracy.

Nanoscribe’s substrate holders guarantee a precise fixation and enable to print on the facet of single fibers, fiber arrays and photonic chips. Furthermore, standard substrates such as microscope slides and wafer formats from 1” to 6” can be easily processed. The advanced interface finder of Quantum X align includes two complementary modes for reflection and fluorescence detection of the substrate surface. In combination with the Dip-in Laser Lithography (DiLL) configuration, a wide range of reflective (e.g. silicon wafers), transparent and opaque substrates (e.g. glass and polymer substrates) can be used.

Dip-in Laser Lithography (DiLL) is the standard printing configuration of Quantum X align. Nanoscribe invented this technology for 3D Microfabrication with the highest precision and the lowest aberration on the market. In this configuration, the objective lens is immersed in the photoresin, which also serves as an optical immersion medium. The refractive index matching between the focusing optics and the print material guarantees ideal, aberration-free focusing with the highest resolution in 2PP-based 3D printing. Furthermore, the writing laser is not focused through the substrate (e.g. oil immersion configuration), but writes the print object directly onto the substrate. Consequently, the working distance of the focusing optics does not limit the height of the 3D-printed object, which is especially beneficial for printing macroscale objects.

The advanced autofocus system reliably finds the interface of any substrate with maximum accuracy and repeatable print results. Three live-view cameras facilitate process control and monitoring. An automatic dispenser applies the correct amount of photoresin onto the substrate, reducing workload and enabling remote operation. To simplify switching between hardware configurations, the Quantum X align automatically detects the printheads and substrate holders. Quantum X align software controls and monitors print jobs in real time and supports intuitive operation through an interactive touchscreen control panel, or remotely from the office via the remote access software nanoConnectX. This remote access also simplifies the work of entire user groups, e.g. members of a research group or a department, with a single or multiple systems, each of them accessing the Quantum X align from their own computer.

Quantum X align is the ideal tool for high-speed 3D Microfabrication of objects with submicron feature sizes, surface roughness profiles of 5 nm and less and nanoscale precision. This highest precision in 3D printing can only be exploited to the maximum by taking some precautions with regard to the system itself and the installation site. Quantum X align should have its fixed place in a room with stable room temperature and humidity. The printer comes with a heavy granite base to reduce the influence of vibrations and temperature fluctuations of the environment. Nevertheless, it is important to install the high-precision printer in a location that minimizes external vibrations. For the handling of the UV-sensitive photoresin outside the printer, we recommend to equip the room with yellow light and to meet basic requirements of a chemistry lab to handle organic solvents for the print development process properly.

If you would like to get an idea of how the Quantum X align work environment can look like, contact us and visit our Microfabrication Experience Center here at Nanoscribe or book your online tour.