Continuous wave and active Q-switched operation of Watt-level LED-pumped two-rod Nd,Ce:YAG laser

A high-performance LED-side-pumped two-rod Nd,Ce:YAG laser with continuous-wave(CW) and acousto–optical(A-O) Q-switched operation is demonstrated in this work. A symmetrically shaped flat–flat cavity with two identical LEDside-pumped laser modules is employed for power scalability. In the CW regime, the maximum output average power of laser at 1064 nm is 4.41 W, corresponding to a maximum optical conversion efficiency of 5.3% and a slope efficiency is 12.4%. In the active Q-switched regime, the pulse energy of laser reaches as high as 0.89 m J at a repetition rate of 800 Hz with a pulse width of 457.2 ns, the corresponding highest peak output power is 1.94 k W and the M~2 factor is measured to be about 8.8. To the best of the authors' knowledge, this is the first demonstration and the highest performance of a CW LED-side-pumped two-rod laser Nd,Ce:YAG with Watt-level output reported so far.

Analysis on financing, investing and operating activities of Target Corporation

The paper analyzes the financing activity, investing activity and operating activity of Target Corporation by comparing with other companies in the same industry. The analysis shows that Target overall is better at meeting it in short-term obligations as well as earning money for its investors. Target is a safe and consistent investment. The company should pay attention to interest rate changes because the company＇s majority of financing charges are based on floating-rate debt obligations.

Prediction Ability of Cash Flows, Net Income （NI）, and Auditors

The accounting information should help investors and creditors evaluate the amounts, timing, and uncertainty of firms＇ future cash receipts and disbursements. The Financial Accounting Standards Board （FASB） contends that accrual-based historical earnings are superior to cash flows in predicting future cash flows. But, Bowen, Burgstahler, and Daley （1986） showed that traditional measures of cash flows （net income （NI） plus depreciation and working capital from operations） appear to be better predictors of future cash flows than accrual accounting earnings. Since then, many researchers have articulated the importance of accounting data, especially cash flows and NI, in the predictive and forecasting processes. In this study, we empirically re-examined the ability of cash flows from operating activities （CFO） and accrual-based NI in predicting firms＇ bankruptcy. In the past, the results of this type of research were mixed. Differently from previous research, we focus on the timing of predictive ability, i.e., which indicator, cash flows or NI, is faster in predicting a firm＇s bankruptcy. We also investigate the timing of auditors＇ issuance of a going-concern opinion. The preliminary results show that the accrual-based NI is more accurate and faster than either CFO or audit opinion in predicting firms＇ failures. On average, NI signals a firm＇s bankruptcy 2.41 years before the bankruptcy filing, while CFO signals 1.48 years before filing. Auditors issued a going-concern opinion, another signal for firms＇ failure, to only 16 out of 41 bankrupt firms one year before bankruptcy, and no auditor issued the going-concern opinion two years before bankruptcy.

Efficient Diode-Pumped Actively Q-Switched Ceramic Nd:YAG/YVO4 Raman Laser Operating at 1657 nm

A diode-pumped actively Q-switched Raman laser is demonstrated, with YV04 employed as Raman active medium, based on a ceramic Nd：YAG laser operating at 1444nm. The first-stokes Raman generation at 1657nm is achieved. A maximum output power of as high as 612mW is obtained under a pump power of 20. 7 W and at a pulse repetition frequency rate of 20kHz, corresponding to an optical-to-optical conversion efficiency of 3%.