Leave a message for inquiry
Leave your phone number, and we'll get in touch with you as soon as possible.
CW & Modulation
Continuous Wave Mode (CW)
The continuous wave (CW) mode of a laser refers to an operational mode where the laser output is continuous in time, uninterrupted, and sustains laser emission. Its core principle is to maintain the gain medium (such as crystals, gases, or semiconductors) in a continuous population inversion state through stable energy pumping. The laser light is continuously reflected and amplified within the optical resonator, ultimately outputting a "continuous and stable laser beam."
Modulation Output Mode (Modulation)
The laser's modulation mode controls and alters output characteristics like intensity and frequency as per user requirements, with two methods: direct power modulation and external transmission modulation.
1. Direct power modulation: Rapidly varying the laser's drive current to control its on/off state or output power. Typically done via TTL or analog signals input through the power supply's external control interface, it is simple to implement but significantly affects the laser's optical properties, including stability, noise, beam spot mode, and linewidth.
(1) Digital Modulation (TTL Modulation)
TTL modulation (Transistor-Transistor Logic Modulation) is a digital modulation method that uses high/low level signals (e.g., 0V and 5V) to control the laser on/off: laser turns on at high level (e.g., 5V) and off at low level (e.g., 0V). Suitable for scenarios requiring rapid laser switching, it enables faster response and high-frequency operation but cannot smoothly adjust power like analog modulation due to its discrete on/off control.
Laser output waveform with digital modulation
(2) Analog Modulation
Analog Modulation controls a laser's output power/intensity by continuously varying analog signals. Typically, it accepts an external voltage input (e.g., 0-5V or 0-10V), with the laser's output power changing accordingly. It allows free adjustment of input signal waveform and amplitude, enabling linear variation of laser power with input voltage. Suitable for scenarios needing smooth, continuous intensity control, such as optical communication, laser processing, or precise scientific research control.
Laser output waveform with analog modulation
2. External Transmission Modulation: The laser outputs continuous light, and mechanical, liquid crystal, electro-optical or acousto-optical devices in the transmission path adjust the laser's properties. The acousto-optic modulator (AOM) is a commonly used external modulation component. The laser only needs to maintain continuous normal output, while the external AOM regulates actual power or controls frequency. Thus, the laser's optical performance remains unaffected, making external modulation recommended for applications with strict requirements on stability, noise, and beam spot.
(1) Acousto-Optic Modulator
AOM is short for Acousto-Optic Modulator. It is a device that uses the acousto-optic effect to control light beams, modulating laser intensity based on input pulse signals. By feeding digital signals (TTL/ Analog) with different encodings and frequencies into the modulator's driver, corresponding digitally encoded optical signals are generated. It is mainly used in fields like laser text-image processing and laser digital communication. Compared to TTL (on-off control) or analog modulation (voltage amplitude control), AOM offers more powerful functionality: it enables more flexible adjustment of optical parameters (intensity, frequency, direction) by the acousto-optic effect, with nanosecond-level response speed.
Single-frequency series high-frequency AOM-modulated laser
(2) Spatial Light Modulator (SLM)
SLM is short for Spatial Light Modulators. As a carrier for digital optical technology, it can alter the amplitude, polarization, or phase of light's spatial distribution (or convert incoherent light to coherent light) under time-varying electrical signals. It easily encodes specific information into light waves for modulation, achieving this by dynamically controlling pixel voltages via real-time image signals. SLM performance largely determines the application value and prospects of modern optical fields like optical information processing, adaptive optics, and optical computing.
For specific types and parameters, please visit https://www.cnilaser.com/C-Spatial-Light-Modulator.htm Understood.
Amplitude-Type/Phase-Type Spatial Light Modulator
The new industry offers highly flexible modulation control solutions, with analog modulation supporting voltage ranges such as 0–5V and 0–10V. TTL modulation can respond to external control frequencies as high as 80 MHz. Additionally, AOM components and tailored solutions are available upon request, enabling response to external control frequencies of up to 30 MHz, with rise and fall times as fast as 10 nanoseconds.
In practical applications, the continuous operation mode of lasers delivers a stable, unwavering beam, making it ideal for scenarios requiring sustained energy input. Meanwhile, the laser's modulation mode excels in offering flexible output, easily adapting to diverse needs—whether for information encoding or precise control applications. Together, these two modes complement each other, continually pushing the boundaries of innovation in industries, communications, and scientific research.
Changchun New Industries Optoelectronics Technology Co., Ltd.
Address: No. 888 Jinhu Road, High-Tech Zone, Changchun, 130103, P.R.China
International Tel:+86-431-85603799
Email: sales@cnilaser.com
Send a Message
Leave your phone number, and we'll get in touch with you as soon as possible.