Comments on “An Efficient Configuration for Significant 175 Enhancement of Energy of 266 nm” published in Journal of Nonlinear Optics and Quantum Optics Vol. 39, No. 4, pp. 315-323 (2009) by S Dutta Roy and S Gangopadhyay
Udit Chatterjee and Gopal Chandra Bhar
The above-mentioned paper published in your journal is not an original contribution. It is neither original in theoretical nor in experimental contribution but in fact duplication and copy from two other papers. This is almost similar to a paper entitled “A new walk-off compensated multipass scheme for large enhancement of conversion efficiency for fourth harmonic generation” already published in Applied Physics B Vol. 97, pp. 129–134 (2009) by these same authors, namely, S. Dutta Roy and S. Gangopadhyay. It is also a silent copy of idea from our original paper published in Applied Optics Vol. 44, No. 5 pp 817–821 (2005) which the authors S. Dutta Roy and S. Gangopadhyay had not mentioned or listed in the Reference list of any of these two publications.