MCAE102-940 is an advanced liquid crystal metasurface optical phased array beam steerer that boasts exceptional performance, with +/-45° optical deflection angle and less than 1mA quiescent current consumption, making it the perfect beam steering device for near infrared sensing applications.
The device uses metasurface technology which uses subwavelength nano structures (pixel) to change the phase of the incident light. In this device, a novel electrically controllable meta pixel is introduced, and the phase of the incident light can be controlled by applying different voltages on each pixel. The pixels with different phases are arranged such that the far field wavefront is steered to different directions.
The device works with MCAD0641 Optical Phased Array Driver. It comes with different active areas for different applications.
| PART NUMBER | APPLICATION | ACTIVE AREA SIZE |
|---|---|---|
| MCAE102-940-1 | Automotive | 8mm x 7mm |
| MCAE102-940-2 | Robotics | 4mm x 4mm |
| Pin No. | Pin name | Pin type | Description |
|---|---|---|---|
| 0, 34, 35, 69 | COM | AIO | Common electrode for all pixels |
| 17, 52 | REF | AIO | Reflection layer |
| 1~16, 18~33, 36~51, 53~68 | Pixel[0]~Pixel[63] | AIO | Pixels for optical phased array |
| Parameter | MIN | MAX | UNIT | |
|---|---|---|---|---|
| VPIX | RMS voltage on pixels | 30 | V | |
| VCOM | RMS voltage on COM pin | 30 | V | |
| VREF | RMS voltage on REF pin | 30 | V | |
| LIDT | Laser induced damage threshold | 50 | J/cm2 | |
| TA | Operating temperature | -25 | 80 | °C |
| Tstg | Storage temperature | -55 | 150 | °C |
| – | Soldering conditions: 260°C, within 10s |
| VALUE | UNIT | ||
|---|---|---|---|
| ESD (Electrostatic discharge) | Human-body model, per ANSI/ESDA/JEDEC JS-001m, all pins | +/-2000 | V |
| Charged-device model (CDM), per JEDEC specification JESD22- C101, all pins | +/-500 | V |
| PARAMETER | MIN | TYP | MAX | UNIT | |
|---|---|---|---|---|---|
| Control Signal | |||||
| VPIX | RMS voltage on pixels | 5 | 8 | V | |
| fPIX | Operating frequency for pixel driving voltage | 10 | 100 | kHz | |
| Incident Beam | 940 | 947 | nm | ||
| Wavelength | 933 | 940 | 947 | nm | |
| Incident angle | 45 | deg | |||
| Polarization: Linearly polarized laser recommended | |||||
| Temperature | |||||
| TA | Operating temperature | -20 | 25 | 70 | °C |
TA = -20~70°C (unless otherwise noted)
| PARAMETER | TEST CONDITIONS | MIN | TYP | MAX | UNIT | |
|---|---|---|---|---|---|---|
| CPIX-PIX | Pixel to pixel capacitance | VPIX = 5Vrms fPIX = 20kHz | 5 | pF | ||
| CPIX-REF | Pixel to REF capacitance | VPIX = 5Vrms fPIX = 20kHz | 0.5 | pF | ||
| CPIX-COM | Pixel to COM capacitance | VPIX = 5Vrms fPIX = 20kHz | 0.1 | pF |
TA = -20~70°C (unless otherwise noted)
| PARAMETER | TEST CONDITIONS | MIN | TYP | MAX | UNIT | |
|---|---|---|---|---|---|---|
| AD | Optical deflection angle | Wavelength = 940nm | -45 | 45 | ° | |
| AR | Beam steering angular resolution | Wavelength = 940nm | 2 | ° | ||
| η | Beam steering efficiency | Wavelength = 940nm | 30 | % | ||
| t | Side lobe suppression | Wavelength = 940nm | 20 | dB |
MCAE102-940 is an advanced solid state optical phased array beam steerer that boasts exceptional performance, with +/-45° optical deflection angle and less than 1mA quiescent current consumption.
The device uses metasurface technology which uses subwavelength nano structures (pixel) to change the phase of the incident light. In this device, a novel electrically controllable meta pixel is introduced, and the phase of the incident light can be controlled by applying different voltages on each pixel. The pixels with different phases are arranged such that the far field wavefront is steered to different directions.
The device works with MCAD0641 Optical Phased Array Driver. MCAD0641 is an optical phased array driver. It generates up to 64-channels of programmable square wave signal to realize the beam steering, with 8-bit resolution. With a MCU, the user can communicate with MCAD0641 driver with SPI interface with steering angle commands.
The device is arranged in the stack-up showing in Figure 6-1. The bottom layer is silicon wafer. To increase the reflectance of the device, a metal reflection layer (REF) is deposited on top of the silicon wafer. On top of the REF layer with some insulation barrier, metasurface nano structures (Pixel) are fabricated. The pixels are several hundreds of nanometers apart and there are thousands of them with in the active area. The pixels are divided into 64 groups and routed to the external pins Pixel[0]~Pixel[63] respectively.
The connections of the pixels are arranged such that the 1st pixel is connected to the 64th pixel, the 2nd pixel is connected to the 65th pixel, and the 3rd pixel is connected to the 66th pixel, and so on so forth.
The reflection layer is also routed to an external pin REF. For best operating stability and noise immunity, it is recommended to connect this pin to REF pin on the MCAD0641 driver, or connect it to GND.
The pixels are equivalent to small capacitances electrically. The RMS voltage applied to CPIX-PIX or CPIX-COM determines the phase response of a pixel. There are two ways to bias a pixel and adjust the phase of a pixel. One way is to keep COM floating and only apply voltages to Pixel[0] ~ Pixel[63]. The other way is to also apply voltage to COM. The equivalent circuit of the pixel structure is shown in Figure 6-2.
The device operates according to phased array principle. The phase of each pixel can be controlled and arranged such that the delta phases between adjacent pixels are equivalent. For different delta phases, the wavefront will tilt in different direction, thus the direction of the beam is steered. The following picture illustrate the operating principle of a phased array.
In MCAE102-940, the phase of each pixel can be adjusted in near 2pi range, so that a close to ideal phased array operation can be achieved. The phase is adjusted by varying the RMS voltage applied to each pixel.
MCAE102-940 is optimized for 45 degrees incident angle with polarization perpendicular with the direction of the nano pixels. The device steers the light +/-45 degrees with reference to the normal direction of the device surface. Figure 6-4 illustrates the incident and outgoing light beam. Figure 6-5 shows the recommended incident light direction and polarization.
MCAE102-940 is intended to be used with MCAD0641 driver. Figure 8-1 shows the typical application diagram. For details on how to program the system. Please refer to the datasheet of MCAD0641.
The MCAE102-940 device is a passive component with no power supply pins. It is equivalent to a network of capacitors between different pins. The capacitors are very small and maybe sensitive in noisy environment. It is recommended to bias all pins according to the application diagram and leave no pin floating except for COM. Layout should be optimized so that the onboard parasitic capacitance of the pins is minimum.
(Preview) MCAD0641 Optical Phased Array Driver with 64 Independent Channels
(Preview) MMAE068-940 3D Time-of-Flight Camera with Meta Beam Steerer
