Chapter 5 Explanation of Laser Parameters
5.1 Introduction to common lasers
以下是根据个人在使用激光器时总结出来的经验，可能会有些错误，仅仅作为参考，不要深信。一般情况下，根据激光的波长进行区分激光器，常见有四种波形的激光器：①1024nm波长激光器，也叫光纤激光器；②355nm波长激光器，一般称作紫外激光器；③532nm激光器，一般称作绿光激光器；④10240nm激光器，也叫CO2激光器；
The following is based on the personal experience of using the laser. There may be some errors. Just for reference, do not believe. In general, lasers are differentiated according to the wavelength of the laser. There are four types of lasers: ① 1024nm laser, also called fiber laser; ② 355nm laser, commonly called ultraviolet laser; ③ 532nm laser, commonly called green laser; ④ 10240nm Laser, also called CO2 laser
5.1.1 Fiber Laser
目前市面上用的较多的是光纤激光器，常见品牌大致有IPG、SPI、JPT、锐科、大族的MP激光器，性能方面我们暂不提，只从能量控制方式上又可以分为两类；
At present, fiber lasers are more commonly used in the market. Common brands include IPG, SPI, JPT, Ruike, and Han's MP lasers. We will not mention performance in terms of performance. They can be divided into two categories based on energy control methods
第一类是IPG、JPT、锐科、大族MP激光器。这几个厂家的激光器，其能量是通过数字量控制，8个引脚一起控制，即8个引脚全部高电平时代表100%能量，全部低电平时0%能量。我们可以理解为那8个引脚就是一个二进制数，二进制11111111，十进制为255，也是100%能量。二进制01111111，十进制127，也就是50%左右能量。0代表低电平，1代表高电平。也可以这么理解：设置PIN1~8的TTL信号，通过TTL信号的组合来设置泵浦激光二极管的电流，即激光器的输出功率。通过PIN1~8可以设置0~255范围内的编码，对应于0%~100%的功率输出（实际光学功率输出可能并非与这些设置成线性关系）
The first type is IPG, JPT, Ruike, and Han MP lasers. The energy of these manufacturers' lasers is controlled digitally, and the 8 pins are controlled together, that is, all 8 pins represent 100% energy at all high levels and 0% energy at all low levels. We can understand that the eight pins are a binary number, 11111111 binary, and 255 decimal, which is also 100% energy. Binary 01111111, decimal 127, which is about 50% energy. 0 means low level and 1 means high level. It can also be understood as follows: Set the TTL signals of PIN1 ~ 8, and set the current of the pump laser diode through the combination of TTL signals, that is, the output power of the laser. Codes in the range of 0 ~ 255 can be set through PIN1 ~ 8, corresponding to 0% ~ 100% power output (the actual optical power output may not be in a linear relationship with these settings)
其中大族MP激光器、JPT激光器，是可以设置脉宽值（单位ns，与Q脉宽是两个概念），在不同的脉宽之下，同样的频率功率，打出来的能量会有差异，一般调节工艺时会需要用到，UDM_SetPulseWidth(unsigned int uPulseWidth)函数可以改变激光器脉宽值。下图为JPT激光器说明说上关于脉宽的截图：
Among them, MP lasers and JPT lasers can set the pulse width value (unit ns, and Q pulse width are two concepts). Under different pulse widths, the same frequency power will produce different energy. Generally It will be used when adjusting the process. The UDM_SetPulseWidth (unsigned int uPulseWidth) function can change the laser pulse width value. The picture below is a screenshot of the pulse width of the JPT laser description.
第二类是SPI激光器，其能量控制是由模拟量控制，0~10V代表0%~100%能量。
在SPI激光器上有个概念叫做波形，其作用等同于调节脉宽，SPI激光器定义了64种波形，0~63号，可以通过下图设置
The second type is SPI laser, whose energy control is controlled by analog, 0 ~ 10V represents 0% ~ 100% energy.
There is a concept on the SPI laser called a waveform, which is equivalent to adjusting the pulse width. The SPI laser defines 64 types of waveforms, 0 to 63, which can be set by the following figure
控制以上激光器，除了能量以外，还需要laserEnable信号（也称MO）、laserOn信号（也称PA）、频率信号，这些信号缺一不可。
In order to control the above lasers, in addition to energy, a laserEnable signal (also called MO), a laserOn signal (also called PA), and a frequency signal are required. These signals are indispensable.
5.1.2 UV, CO2, green laser
相对于光纤激光器，这三种类型的激光器控制上比较简单，一般情况下，只需要一个Q频率信号就能控制其开关光，其能量大小由占空比决定（占空比=脉宽/周期）。遇到此类激光器时，需要把不出光Q频率与不出光Q脉宽设置成0，否则激光器会一直出光，无法关闭。CO2激光器会灼伤皮肤，请务必注意安全。
Compared to fiber lasers, these three types of lasers are relatively simple to control. Generally, only a Q-frequency signal is needed to control the switching light. The energy is determined by the duty cycle (duty cycle = pulse width / period). ). When encountering such a laser, you need to set the non-light-emitting Q frequency and the non-light-emitting Q pulse width to 0, otherwise the laser will always emit light and cannot be turned off. The CO2 laser burns your skin, so be careful.
5.1.3 About the laser frequency
像光纤激光器这种，要控制它出光，其所需信号多达十几个，所有信号均满足时才能出光，因此，其不出光Q频率与不出光Q脉宽可以不设置成0，尽量让不出光Q频率等于出光Q频率、不出光Q脉宽等于出光Q脉宽。
Like a fiber laser, to control its light output, it needs more than a dozen signals, and all of the signals can be output. Therefore, its non-light Q frequency and non-light Q pulse width can be set to 0. The non-exit Q frequency is equal to the output Q frequency, and the non-exit Q pulse width is equal to the output Q pulse width.
注意：若强行把不出光Q频率脉宽设置成0，对于某些性能不好的激光器来说，其反应较慢，会造成起点频率异常，激光点间距以及点能量异常，建议都设置成一样，可以避免此现象。另外占空比最好是0.5，也就是Q脉宽是Q周期的一半。
Note: If the Q-frequency pulse width is not set to 0 forcibly, for some lasers with poor performance, the response will be slower, which will cause abnormal starting frequency, laser dot spacing and dot energy. It is recommended to set the same. To avoid this phenomenon. In addition, the duty cycle is preferably 0.5, which means that the Q pulse width is half of the Q period.
像CO2、紫外、绿光等激光器，它只需要一个Q频率与Q脉宽信号，因此必须把不出光Q频率与不出光Q脉宽设置成0，否则激光无法关闭。当然，部分厂家激光器除了此信号外，可能也需要laseron信号，这时候，是不是设置0就不影响了。
Like CO2, UV, green, and other lasers, it only needs one Q frequency and Q pulse width signal. Therefore, the non-lighting Q frequency and non-lighting Q pulse width must be set to 0, otherwise the laser cannot be turned off. Of course, in addition to this signal, some manufacturers' lasers may also require a laseron signal. At this time, it does not matter if it is set to 0.
5.2 Description of laser units
在DEMO中给激光器参数赋值时，都有个*100的操作，如下图所示：
When assigning values to laser parameters in DEMO, there is a * 100 operation, as shown in the figure below:
之所以如此，是因为激光器接受的单位是10ns，即最小控制周期为10ns，所以结构体中的单位也默认为10ns。但是一般在激光工艺加工中，习惯用us做单位，因此要把界面输入的us单位时间，转成10ns做单位。比如输入10us，则转成10ns为单位。最终值为10*100，即1000个10ns。若用户输入50us，则最终值为50*100个10ns，以此类推。
The reason for this is that the unit accepted by the laser is 10ns, that is, the minimum control period is 10ns, so the unit in the structure is also 10ns by default. However, in laser processing, it is customary to use us as the unit, so the unit time of the us input on the interface must be converted into 10ns as the unit. For example, if you enter 10us, it will be converted into 10ns. The final value is 10 * 100, which is 1000 10ns. If the user enters 50us, the final value is 50 * 100 10ns, and so on.
5.3 About the concepts of Q frequency, Q pulse width, and Q period
Q周期（T）与Q频率（F）是倒数关系，即T=1/F。周期单位为秒（S），频率单位为赫兹（HZ）。通常在激光器行业中，一般用Q频率做单位，不用Q周期，因此用户在界面上输入频率后，需要转换成Q周期给控制卡。
The Q period (T) and the Q frequency (F) have an inverse relationship, that is, T = 1 / F. The period unit is seconds (S) and the frequency unit is hertz (HZ). Usually in the laser industry, the Q frequency is generally used as the unit, and the Q period is not used. Therefore, after the user inputs the frequency on the interface, it needs to be converted to the Q period for the control card.
如果用户输入20K的频率，则对应Q周期为1/20K=0.00005s=0.05ms=50us，需要将50us转成10ns的单位发给控制卡。需要说明Q周期≥Q脉宽，否则关系不成立。
If the user inputs a frequency of 20K, the corresponding Q period is 1 / 20K = 0.00005s = 0.05ms = 50us, and 50us needs to be converted into a unit of 10ns and sent to the control card. It needs to be explained that Q period ≥ Q pulse width, otherwise the relationship does not hold.
用户也可以再此基础上定义一个变量，叫做占空比。这样可简化为这样的公式：
假设用户输入频率为frequency（KHz），占空比为dutyCycle（0~100%）。
The user can also define a variable based on this, called the duty cycle. This can be simplified to this formula:
Assume that the user input frequency is frequency (KHz) and the duty cycle is dutyCycle (0 ~ 100%).
那么QPeriod(周期)= (int)(100000 / frequency);此值已经转成了10ns的单位
QWidth = QPeriod * dutyCycle = (int)(100000 * dutyCycle / frequency)；此值已经转成了10ns的单位
Then QPeriod (period) = (int) (100000 / frequency); this value has been converted into units of 10ns
QWidth = QPeriod * dutyCycle = (int) (100000 * dutyCycle / frequency); this value has been converted into units of 10ns
把这两个值直接赋值给结构体中的相关变量即可
Assign these two values directly to the relevant variables in the structure
如果是激光扫描振镜光纤激光器，建议占空比dutyCycle为50%。
如果是CO2这种类型的激光器，其能量是由占空比决定，因此建议把界面上的能量百分比赋值给占空比，如用户输入50%能量，则dutyCycle=50%。
If it is a fiber laser, the duty cycle dutyCycle is recommended to be 50%.
If it is a CO2 laser, its energy is determined by the duty cycle. Therefore, it is recommended to assign the energy percentage on the interface to the duty cycle. If the user inputs 50% energy, dutyCycle = 50%.
