In the precision field of optical modulation technology, the 1550nm space acousto-optic modulator (AOM) provides key support for many fields such as laser radar, material processing, and optical communication with its unique performance. The 1550nm space AOM with different center frequencies, such as 100MHz and 200MHz models, have their own characteristics in performance parameters, which are fully analyzed below.

Frequency characteristics and modulation bandwidth

As the basic parameter of AOM, the center frequency of 100MHz and 200MHz determines the basic frequency reference of its modulated laser. The 200MHz model theoretically has a wider modulation bandwidth, which can achieve higher frequency signal modulation. In the field of optical communications, if high-speed data transmission is required, the 200MHz AOM can modulate the frequency and intensity of optical signals more quickly, load complex data information into the optical copyright, and meet the data transmission requirements of 100Gbps or even higher rates; while the 100MHz AOM can stably achieve signal modulation and ensure reliable data transmission in some medium- and low-speed optical communication scenarios that have relatively low bandwidth requirements and focus on stability, such as some industrial control optical communication links.

Diffraction efficiency and light energy utilization

The diffraction efficiency of both AOMs is ≥80%, but they perform differently in actual application scenarios. In long-distance detection of LiDAR, 200MHz AOM can maintain high diffraction efficiency during high-frequency scanning due to its modulation bandwidth advantage, convert more emitted laser energy into effective detection beams, improve echo signal strength, and enable radar to clearly detect targets at longer distances (such as in complex terrain mapping, it can increase the effective detection distance by 10%-20%); 100MHz AOM is used in LiDAR applications with relatively close distances and not requiring extreme scanning frame rates, such as indoor robot navigation LiDAR, with stable diffraction efficiency, to ensure efficient use of laser energy and accurately build maps of the surrounding environment.

Optical pulse rise time and modulation speed

The 1550nm space AOM optical pulse rise time reaches 160ns/mm. The 200MHz model has more advantages in fast modulation scenarios due to its higher frequency response capability. In ultrashort pulse laser cutting of material processing, 200MHz AOM can switch the laser "on-off" state faster, generate a laser pulse sequence with narrower pulse width and higher peak power, and perform fine cutting on brittle materials (such as glass). The heat-affected zone can be reduced to the micron level; 100MHz AOM can meet the modulation frequency requirements of thousands of times per second in conventional material processing, such as metal sheet welding, stably control the laser energy output, and achieve high-quality welding.

Frequency offset bandwidth and application adaptation

The frequency offset bandwidth of 100MHz AOM is 30MHz, and that of 200MHz is 50MHz. In the laser Doppler speed measurement system, the wider frequency offset bandwidth of 200MHz AOM can measure the speed of objects with higher speed and more complex motion, such as measuring the linear speed of aircraft engine blades rotating at high speed, and can accurately capture instantaneous speed changes; 100MHz AOM is suitable for object speed measurement in general industrial scenarios, such as conveyor belt speed monitoring, with stable frequency offset to accurately calculate the object movement speed.

Damage threshold and durability

Both AOMs have a damage threshold of 10W/mm2 and can withstand certain high-power laser irradiation. However, in high-power, long-term continuous material processing (such as continuous laser engraving) or high-energy laser experiment scenarios, the 200MHz AOM has a fast modulation speed and strong ability to process high-frequency signals. It processes more light energy in the same time. If auxiliary measures such as heat dissipation are not in place, it may face a higher risk of damage; the 100MHz AOM can rely on stable performance to ensure long-term durability in relatively low-power, intermittent applications, such as small laser marking equipment.

The 1550nm space AOM of 100MHz and 200MHz has different focuses on performance parameters. In actual applications, it is necessary to accurately select the appropriate model according to the specific scenario (such as optical communication rate requirements, laser radar detection distance and frame rate, material processing accuracy and power), give full play to its performance advantages, provide reliable optical modulation support for the efficient operation of optoelectronic systems, and promote the continuous innovation and development of optical technology applications in various fields.