Chapter 5 Explanation of Laser Parameters
5.1 Introduction to common lasers
以下是根據(jù)個(gè)人在使用激光器時(shí)總結(jié)出來(lái)的經(jīng)驗(yàn)，可能會(huì)有些錯(cuò)誤，僅僅作為參考，不要深信。一般情況下，根據(jù)激光的波長(zhǎng)進(jìn)行區(qū)分激光器，常見(jiàn)有四種波形的激光器：①1024nm波長(zhǎng)激光器，也叫光纖激光器；②355nm波長(zhǎng)激光器，一般稱(chēng)作紫外激光器；③532nm激光器，一般稱(chēng)作綠光激光器；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
目前市面上用的較多的是光纖激光器，常見(jiàn)品牌大致有IPG、SPI、JPT、銳科、大族的MP激光器，性能方面我們暫不提，只從能量控制方式上又可以分為兩類(lèi)；
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
第一類(lèi)是IPG、JPT、銳科、大族MP激光器。這幾個(gè)廠家的激光器，其能量是通過(guò)數(shù)字量控制，8個(gè)引腳一起控制，即8個(gè)引腳全部高電平時(shí)代表100%能量，全部低電平時(shí)0%能量。我們可以理解為那8個(gè)引腳就是一個(gè)二進(jìn)制數(shù)，二進(jìn)制11111111，十進(jìn)制為255，也是100%能量。二進(jìn)制01111111，十進(jìn)制127，也就是50%左右能量。0代表低電平，1代表高電平。也可以這么理解：設(shè)置PIN1~8的TTL信號(hào)，通過(guò)TTL信號(hào)的組合來(lái)設(shè)置泵浦激光二極管的電流，即激光器的輸出功率。通過(guò)PIN1~8可以設(shè)置0~255范圍內(nèi)的編碼，對(duì)應(yīng)于0%~100%的功率輸出（實(shí)際光學(xué)功率輸出可能并非與這些設(shè)置成線性關(guān)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，是可以設(shè)置脈寬值（單位ns，與Q脈寬是兩個(gè)概念），在不同的脈寬之下，同樣的頻率功率，打出來(lái)的能量會(huì)有差異，一般調(diào)節(jié)工藝時(shí)會(huì)需要用到，UDM_SetPulseWidth(unsigned int uPulseWidth)函數(shù)可以改變激光器脈寬值。下圖為JPT激光器說(shuō)明說(shuō)上關(guān)于脈寬的截圖：
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.
第二類(lèi)是SPI激光器，其能量控制是由模擬量控制，0~10V代表0%~100%能量。
在SPI激光器上有個(gè)概念叫做波形，其作用等同于調(diào)節(jié)脈寬，SPI激光器定義了64種波形，0~63號(hào)，可以通過(guò)下圖設(shè)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，還需要laserEnable信號(hào)（也稱(chēng)MO）、laserOn信號(hào)（也稱(chēng)PA）、頻率信號(hào)，這些信號(hào)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
相對(duì)于光纖激光器，這三種類(lèi)型的激光器控制上比較簡(jiǎn)單，一般情況下，只需要一個(gè)Q頻率信號(hào)就能控制其開(kāi)關(guān)光，其能量大小由占空比決定（占空比=脈寬/周期）。遇到此類(lèi)激光器時(shí)，需要把不出光Q頻率與不出光Q脈寬設(shè)置成0，否則激光器會(huì)一直出光，無(wú)法關(guān)閉。CO2激光器會(huì)灼傷皮膚，請(qǐng)務(wù)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
像光纖激光器這種，要控制它出光，其所需信號(hào)多達(dá)十幾個(gè)，所有信號(hào)均滿足時(shí)才能出光，因此，其不出光Q頻率與不出光Q脈寬可以不設(shè)置成0，盡量讓不出光Q頻率等于出光Q頻率、不出光Q脈寬等于出光Q脈寬。
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：若強(qiáng)行把不出光Q頻率脈寬設(shè)置成0，對(duì)于某些性能不好的激光器來(lái)說(shuō)，其反應(yīng)較慢，會(huì)造成起點(diǎn)頻率異常，激光點(diǎn)間距以及點(diǎn)能量異常，建議都設(shè)置成一樣，可以避免此現(xiàn)象。另外占空比最好是0.5，也就是Q脈寬是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、綠光等激光器，它只需要一個(gè)Q頻率與Q脈寬信號(hào)，因此必須把不出光Q頻率與不出光Q脈寬設(shè)置成0，否則激光無(wú)法關(guān)閉。當(dāng)然，部分廠家激光器除了此信號(hào)外，可能也需要laseron信號(hào)，這時(shí)候，是不是設(shè)置0就不影響了。
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中給激光器參數(shù)賦值時(shí)，都有個(gè)*100的操作，如下圖所示：
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?yàn)榧す馄鹘邮艿膯挝皇?/span>10ns，即最小控制周期為10ns，所以結(jié)構(gòu)體中的單位也默認(rèn)為10ns。但是一般在激光工藝加工中，習(xí)慣用us做單位，因此要把界面輸入的us單位時(shí)間，轉(zhuǎn)成10ns做單位。比如輸入10us，則轉(zhuǎn)成10ns為單位。最終值為10*100，即1000個(gè)10ns。若用戶輸入50us，則最終值為50*100個(gè)10ns，以此類(lèi)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）與Q頻率（F）是倒數(shù)關(guān)系，即T=1/F。周期單位為秒（S），頻率單位為赫茲（HZ）。通常在激光器行業(yè)中，一般用Q頻率做單位，不用Q周期，因此用戶在界面上輸入頻率后，需要轉(zhuǎn)換成Q周期給控制卡。
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.
如果用戶輸入20K的頻率，則對(duì)應(yīng)Q周期為1/20K=0.00005s=0.05ms=50us，需要將50us轉(zhuǎn)成10ns的單位發(fā)給控制卡。需要說(shuō)明Q周期≥Q脈寬，否則關(guān)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.
用戶也可以再此基礎(chǔ)上定義一個(gè)變量，叫做占空比。這樣可簡(jiǎn)化為這樣的公式：
假設(shè)用戶輸入頻率為frequency（KHz），占空比為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);此值已經(jīng)轉(zhuǎn)成了10ns的單位
QWidth = QPeriod * dutyCycle = (int)(100000 * dutyCycle / frequency)；此值已經(jīng)轉(zhuǎn)成了10ns的單位
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
把這兩個(gè)值直接賦值給結(jié)構(gòu)體中的相關(guān)變量即可
Assign these two values directly to the relevant variables in the structure
如果是激光掃描振鏡光纖激光器，建議占空比dutyCycle為50%。
如果是CO2這種類(lèi)型的激光器，其能量是由占空比決定，因此建議把界面上的能量百分比賦值給占空比，如用戶輸入50%能量，則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%.
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